Deprecation warnings showing up `'[Return]' setting is deprecated`

[consideRatio]

I think the following warnings seen in https://github.com/jupyterhub/jupyter-server-proxy/actions/runs/7957862509/job/21721594362 is related to this project.

Here is an example where [Return] is used:

robotframework-jupyterlibrary/src/JupyterLibrary/common/CodeMirror.resource

Line 24 in 9e25fcb

[Return] ${result}

These deprecation warnings may have started to appear using jupyterlab-4.1.1 notebook-7.1.0 compared to jupyterlab-4.0.12 notebook 7.0.8, but I'm not confident on what provides the warning so I'm confused. Using jupyterhub/jupyter-server-proxy's test suite, they show up for the test_robot pytest when using notebook 7.1.0 but not when using notebook 7.0.8.

==============================================================================
Acceptance :: Acceptance tests for jupyter-server-proxy                       
==============================================================================
Acceptance.Lab :: Server Proxies in Lab                                       
==============================================================================
Lab Loads                                                             | PASS |
------------------------------------------------------------------------------
Launch Browser Tab                                                    | PASS |
------------------------------------------------------------------------------
Launch Lab Tab                                                        | PASS |
------------------------------------------------------------------------------
Acceptance.Lab :: Server Proxies in Lab                               | PASS |
3 tests, 3 passed, 0 failed
==============================================================================
Acceptance.Notebook :: Server Proxies in Notebook                             
==============================================================================
Notebook Loads                                                        | PASS |
------------------------------------------------------------------------------
Launch Browser Tab                                                    | FAIL |
Element with locator 'xpath://div[contains(@class, "jp-FileBrowser-toolbar")]//*[contains(text(), "New")]' not found.
------------------------------------------------------------------------------
Launch Another Browser Tab                                            | FAIL |
Element with locator 'xpath://div[contains(@class, "jp-FileBrowser-toolbar")]//*[contains(text(), "New")]' not found.
------------------------------------------------------------------------------
Acceptance.Notebook :: Server Proxies in Notebook                     | FAIL |
3 tests, 1 passed, 2 failed
==============================================================================
Acceptance :: Acceptance tests for jupyter-server-proxy               | FAIL |
6 tests, 4 passed, 2 failed
==============================================================================
Output:  /home/erik/dev/jupyterhub/jupyter-server-proxy/build/robot/output.xml
Log:     /home/erik/dev/jupyterhub/jupyter-server-proxy/build/robot/log.html
Report:  /home/erik/dev/jupyterhub/jupyter-server-proxy/build/robot/report.html
---------------------------------------------------------------------------------------------------------- Captured stderr call ----------------------------------------------------------------------------------------------------------
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 24: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 39: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 46: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 53: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 61: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 68: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 76: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/common/CodeMirror.resource' on line 85: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/Shortcuts.resource' on line 14: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/Icons.resource' on line 38: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/Icons.resource' on line 47: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/PageInfo.resource' on line 28: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/PageInfo.resource' on line 57: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/Settings.resource' on line 19: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/Settings.resource' on line 30: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/Settings.resource' on line 62: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.
[ WARN ] Error in file '/home/erik/miniforge3/lib/python3.10/site-packages/JupyterLibrary/clients/jupyterlab/Shell.resource' on line 84: The '[Return]' setting is deprecated. Use the 'RETURN' statement instead.