feat(ci): validate checklist is updated

[Molter73]

Description

This is a small CI check that verifies a few fields in the checklist section of the PR description is updated. If this is not too disruptive, we can probably make the check required in the near future.

Checklist

• Patch has a change log entry OR does not need one
• Investigated and inspected CI test results
• Updated documentation accordingly

Automated testing

• Added unit tests
• Added integration tests
• Added regression tests

If any of these don't apply, please comment below.

Testing Performed

• Check is skipped for draft PRs: CI run.
• Change log check fails when not set: CI run.
• CI check fails when not set: CI run
• Job passes when both entries are set: CI run