Remove "I have added an entry to CHANGELOG.md" from the PR template

[dbeatty10]

resolves #902

This is a:

• under the hood change

All pull requests from community contributors should target the main branch (default).

Problem

We have a checklist item reminding contributors to manually update the changelog. But we have been using the "Generate release notes" button in GitHub in place of manual changelog entries. So any changelog entries that are merged are just overwritten during the release.

Also, we have a long checklist, which lowers its utility.

Solution

• Remove "I have added an entry to CHANGELOG.md" from the PR template
• Checklist is one item shorter

Checklist

• This code is associated with an Issue which has been triaged and accepted for development.