[JENKINS-74030] Extract inline script from ChoiceParameter/index.jelly

[yaroslavafenkin]

https://issues.jenkins.io/browse/JENKINS-74030

Testing done

Created a freestyle project with 2 Active Choices Parameters. Took sample Groovy scripts from the README. It's important to check Enable filters so that the script is included into the page.

Before the change
After the change

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[kinow]

Thank you for the pull request and explaining the testing done, @yaroslavafenkin ! The code looks good, but I will need to read the issue linked again to review it (will probably check the caniuse it too for DOMContentLoaded as I don't remember using it directly -- not sure if available/supported by every browser).

[yaroslavafenkin]

Thank you for the pull request and explaining the testing done, @yaroslavafenkin ! The code looks good, but I will need to read the issue linked again to review it (will probably check the caniuse it too for DOMContentLoaded as I don't remember using it directly -- not sure if available/supported by every browser).

That's the approach recommended in https://www.jenkins.io/doc/developer/security/csp/#inline-event-handlers. But sure, no rush from my side. Thanks for your quick reaction.

[kinow]

caniuse is green for every browser, and thanks for the Jenkins link. Re-read the change this morning ☕ and everything looks great. Will merge both PRs. Thanks a lot @yaroslavafenkin !