Small changie fixes

[emmyoop]

resolves #4848

Description

1. fixes broken links in the PR comment and changelog itself to point to our directions in the contributing docs on how to add a changelog.
2. Comment that a changelog entry is required will only post once but GHA will continue to fail until the file is added.

Checklist

• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have added information about my change to be included in the CHANGELOG.

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the contributing guide.

[github-actions]

The backport to 1.0.latest failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-1.0.latest 1.0.latest
# Navigate to the new working tree
cd .worktrees/backport-1.0.latest
# Create a new branch
git switch --create backport-4857-to-1.0.latest
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 0fce63665cd8a45fbc069c02ae174e194ed5892b
# Push it to GitHub
git push --set-upstream origin backport-4857-to-1.0.latest
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-1.0.latest

Then, create a pull request where the base branch is 1.0.latest and the compare/head branch is backport-4857-to-1.0.latest.