build(deps): bump peter-evans/create-pull-request in the actions group (sigstore#1315)

Bumps the actions group with 1 update: [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request).


Updates `peter-evans/create-pull-request` from 7.0.7 to 7.0.8
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](peter-evans/create-pull-request@dd2324f...271a8d0)

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

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

Author: dependabot[bot]

.github/workflows/pin-requirements.yml

@@ -129,7 +129,7 @@ jobs:
           git push -f origin "origin/main:${SIGSTORE_PIN_REQUIREMENTS_BRANCH}"
 
       - name: Open pull request
-        uses: peter-evans/create-pull-request@dd2324fc52d5d43c699a5636bcf19fceaa70c284 # v7.0.7
+        uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e # v7.0.8
         with:
           title: |
             Update pinned requirements for ${{ env.SIGSTORE_RELEASE_TAG }}