Add CI check for PR title being in past tense

All the PR titles get written to the CHANGELOG file through auto release

I standardize them to follow the past tense since that is a clear statement on the history of changes, e.g. "Updated model fields to the latest BEP32 state" and consistency is good

I do this manually ATM but something *might* slip through the cracks if I'm not careful. Can always be corrected after the fact but better to catch it before merge

This seems like a small independent improvement that either of you could work on during a future nwb2bids WG @candleindark @asmacdo

No file or test is identified. Start by locating the repository's CI configuration and the automation that writes CHANGELOG entries, then establish how PR titles will be checked for past tense. Done means the check runs before merge, accepts titles like "Updated model fields to the latest BEP32 state," and rejects titles that do not meet the agreed rule.

Written by the indexing model from the issue text.