Raise ModuleNotFoundError for Jinja use without the dependency

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: thibaudcolas

pattern_library/monkey_utils.py

@@ -134,8 +134,7 @@ def override_jinja_tags():
         from jinja2.compiler import CodeGenerator as JinjaCodeGenerator
         from jinja2.environment import Template as JinjaTemplate
     except ModuleNotFoundError:
-        ModuleNotFoundError("install jinja2 to override jinja tags")
-
+        raise ModuleNotFoundError("install jinja2 to override jinja tags")
     from pattern_library.loader_tags import template_new_context, visit_extends
 
     jinja_visit_Extends = JinjaCodeGenerator.visit_Extends