Merge main into v1

[github-actions]

Merging f6d1bad into v1

Conductor for this PR is @robertbrignull

Contains the following pull requests:

• Check if on default branch before uploading database #563 - Check if on default branch before uploading database (@robertbrignull)
• Provide a better error message #564 - Provide a better error message (@robertbrignull)
• Only attempt to upload on dotcom #565 - Only attempt to upload on dotcom (@robertbrignull)
• Add a CODEOWNERS file #569 - Add a CODEOWNERS file (@aeisenberg)
• Upload CodeQL databases #573 - Upload CodeQL databases (@robertbrignull)

Please review the following:

• The CHANGELOG displays the correct version and date.
• The CHANGELOG includes all relevant, user-facing changes since the last release.
• There are no unexpected commits being merged into the v1 branch.
• The docs team is aware of any documentation changes that need to be released.
• The mergeback PR is merged back into main after this PR is merged.

[robertbrignull]

Aborting this release for now. I've spotted some problems in the database upload work which will probably require reverting those changes from the main branch too while we can work on fixing it and adding necessary tests.

Since the only other change in this PR was adding a codeowners file, which doesn't need to be on the v1 branch, I think just aborting this release entirely is likely fine.