Bump tibdex/backport from 1 to 2

Bumps [tibdex/backport](https://github.com/tibdex/backport) from 1 to 2.
- [Release notes](https://github.com/tibdex/backport/releases)
- [Commits](tibdex/backport@v1...v2)

---
updated-dependencies:
- dependency-name: tibdex/backport
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/Backport.yml

@@ -11,6 +11,6 @@ jobs:
  name: Backport
  steps:
  - name: Backport
- uses: tibdex/backport@v1
+ uses: tibdex/backport@v2
  with:
  github_token: ${{ secrets.GITHUB_TOKEN }}