devel/freebsd-git-devtools: Update to 20230925 snapshot

This update pulls in src commit 61f8df6a13, which updates mfc-candidates
to search by committer and not both author and committer.

https://cgit.freebsd.org/src/commit/tools/tools/git/mfc-candidates.sh?id=61f8df6a13a357e1d45c22a2016b87491f10de87

Sponsored by: The FreeBSD Foundation