Boost dashboard: fix display of upsell in critical CSS modal

[jeherve]

Fixes HOG-75 -- Dashboard: display issues in upsell in Critical CSS modal

Proposed changes:

The text within the upsell is displayed on a single line:

Before

After

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

• N/A

Does this pull request change what data or activity we track or use?

• No

Testing instructions:

• Start with a site running Boost free
• Go to Jetpack > Boost
• Click on the "info" icon after You should regenerate your Critical CSS whenever you make changes to the HTML or CSS structure of your site.
• Ensure the upsell at the bottom of the modal is displayed properly (see screenshot above).

[github-actions]

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Boost plugin:

• Next scheduled release: April 30, 2025

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[jp-launch-control]

Code Coverage Summary

This PR did not change code coverage!

That could be good or bad, depending on the situation. Everything covered before, and still is? Great! Nothing was covered before? Not so great. 🤷

Full summary · PHP report · JS report

[haqadn]

Nice! I just discovered that the CTA doesn't do anything on click. I'll log it in a separate issue.