Bump peter-evans/create-pull-request from 6 to 7 (#967)

Bumps [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request) from 6 to 7.
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](https://github.com/peter-evans/create-pull-request/compare/v6...v7)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/autoprefixer.yml

@@ -21,7 +21,7 @@ jobs:
           npm run autoprefixer
 
       - name: Create Pull Request
-        uses: peter-evans/create-pull-request@v6
+        uses: peter-evans/create-pull-request@v7
         with:
           branch: autoprefixer
           branch-suffix: timestamp