Stop requesting changelogs in PRs

We added this requirement before the changelog was automated. Now that the changelog generated by a script, it's not helpful for PRs to update the changelog anymore, so we shouldn't expect it anymore.

doc/development/PULL_REQUESTS.md

@@ -34,7 +34,3 @@ Please ensure that the commit messages included in the pull request __do not__ h
 If you want to use these mechanisms, please instead include them in the pull request description. This prevents multiple notifications or references being created on commit rebases or pull request/branch force pushes.
 
 Additionally, do not use `[ci skip]` or `[skip ci]` mechanisms in your pull request titles/descriptions or commit messages. Every potential commit and pull request should run through Bundler's CI system. This applies to all changes/commits (ex. even a change to just documentation or the removal of a comment).
-
-## CHANGELOG.md
-
-Don't forget to add your changes into the CHANGELOG! If you're submitting documentation, note the changes under the "Documentation" heading.