fix(git): fix gpg commit signing

[candrews]

Changes

The value for git gpg.format should be openpgp not opengpg

See: https://git-scm.com/docs/git-config#Documentation/git-config.txt-gpgformat

This confusion is well described by https://sethmlarson.dev/switching-git-back-to-gpg-signing

Context

Fixed regression introduced by #29550 (comment) in Renovate 38.46.0

Documentation (please check one with an [x])

• I have updated the documentation, or
• No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests but ran on a real repository, or
• Both unit tests + ran on a real repository

[renovate-release]

🎉 This issue has been resolved in version 38.46.2 🎉

The release is available on:

• GitHub release
• npm package (@latest dist-tag)
• 38.46.2

Your semantic-release bot 📦🚀