fix: remove the update changelog entry

[LucaLanziani]

No need to update the changelog since it's something that release please does by itself.

What does this PR do?

Remove one outdated checkbox from the PR template file

Checklist before merging

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have checked the contributing document.
• I have checked the existing Pull Requests to see whether someone else has raised a similar idea or question.
• I have added tests that prove my fix is effective or that my feature works.
• I have upgraded the changelog according to the nature of the feature that I am adding to this Pull Request.