base-revsets: use an author that actually exercises a lot of changesets This was caught in my big find-and-replace: d4ba4d51f85f. The point of `base-revsets` is to give revsets that will give a good coverage of the repository. Using Pierre-Yves as the second largest committer (in terms of number of changesets) seems like a good idea.

# So GitLab doesn't think we're using tons of Perl
*.t -linguist-detectable