Removed pr-tools.yml (#1999)

This PR is a followup to #1996 - that PR disabled pr-tools.yml due to a security vulnerability but left the contents of the file commented out. It turns out that GitHub Actions complains about yml files that do nothing, so this PR removes the file entirely.

Signed-off-by: Joshua Minor <jminor@users.noreply.github.com>

Author: jminor