Bump peter-evans/create-pull-request from 7 to 8 (#2610)

Bumps [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request) from 7 to 8.
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](https://github.com/peter-evans/create-pull-request/compare/v7...v8)

---
updated-dependencies:
- dependency-name: peter-evans/create-pull-request
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/fetch_external_docs_reusable.yml

@@ -114,7 +114,7 @@ jobs:
 
       # Create an automated pull request, if the resulting branch is ahead of the `base-target-branch`
       - name: Create pull request
-        uses: peter-evans/create-pull-request@v7
+        uses: peter-evans/create-pull-request@v8
         with:
           commit-message: Automated ${{ inputs.base_source_repository }} Docs fetch
           committer: openHAB Bot <info@openhab.org>