Bump the prod-dependencies group with 2 updates

Bumps the prod-dependencies group with 2 updates: [@antora/cli](https://gitlab.com/antora/antora) and [@antora/site-generator-default](https://gitlab.com/antora/antora).


Updates `@antora/cli` from 3.1.10 to 3.1.12
- [Changelog](https://gitlab.com/antora/antora/blob/main/CHANGELOG.adoc)
- [Commits](https://gitlab.com/antora/antora/compare/v3.1.10...v3.1.12)

Updates `@antora/site-generator-default` from 3.1.10 to 3.1.12
- [Changelog](https://gitlab.com/antora/antora/blob/main/CHANGELOG.adoc)
- [Commits](https://gitlab.com/antora/antora/compare/v3.1.10...v3.1.12)

---
updated-dependencies:
- dependency-name: "@antora/cli"
  dependency-version: 3.1.12
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: prod-dependencies
- dependency-name: "@antora/site-generator-default"
  dependency-version: 3.1.12
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: prod-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]