Auto-approve and in some cases auto-merge Dependabot PRs

[grahamalama]

• Auto-approve all PRs
• For production dependencies, auto-merge patch updates
• For non-production dependencies, auto-merge all updates

See also:
mozilla-it/ctms-api#584

[grahamalama]

Other things we had to do to enable this:

• Disable the branch protection rule to require a CODEOWNER approval:

• Specify status checks that must pass before allowing a merge

One TODO I discovered in adjusting these settings was to rename the job id in lint.yaml from run_test to run_lint.

• add a requires-manual-qa label. This is what the Github Actions automation bot applies to Dependabot PRs for minor or major semver bumps to production dependencies