Add reminder that pin must be in sync with two other places

[jsf9k]

🗣 Description

This pull request modifies a comment to remind us that the ansible-core pin must stay in sync across this repo as well as:

• cisagov/skeleton-generic
• cisagov/skeleton-packer

💭 Motivation and context

If we update the pin in one place we must remember to update it in the two other places.

🧪 Testing

All automated tests pass.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All new and existing tests pass.

[jsf9k]

We can close this pull request because a new version of the ansible-core Python package has been released that does not suffer from the bug discussed in ansible/ansible#82702. This bug broke any symlinked files in vars, tasks, etc. for any Ansible role installed via ansible-galaxy.

See also #193.