build(deps): bump signpath/github-action-submit-signing-request

Bumps [signpath/github-action-submit-signing-request](https://github.com/signpath/github-action-submit-signing-request) from 1 to 2.
- [Release notes](https://github.com/signpath/github-action-submit-signing-request/releases)
- [Commits](https://github.com/signpath/github-action-submit-signing-request/compare/v1...v2)

---
updated-dependencies:
- dependency-name: signpath/github-action-submit-signing-request
  dependency-version: '2'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>