Remove db lock file

[jgraham]

This keeps getting deleted locally; presumably we don't actually want a lockfile commited to the repo.

Checklist

• Type annotations added to new functions
• Docs added to functions touched in main classes
• Dry-run produced the expected results
• The to-be-announced tag added if this is worth announcing

[jgraham]

Interesting; I didn't see breakage with this locally, and the file keeps getting deleted and showing up as a local change, which was why I made this PR.

[suhaibmujahid]

The file is used when running something that utilizes the SQLite database, which is used for caching in some areas.