Update peter-evans/create-pull-request action to v8 (#2973)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Radoslav Dimitrov <radoslav@stacklok.com>

Author: renovate[bot]

.github/workflows/update-registry.yml

@@ -98,7 +98,7 @@ jobs:
 
       - name: Create Pull Request
         if: steps.update.outputs.changes == 'true'
-        uses: peter-evans/create-pull-request@22a9089034f40e5a961c8808d113e2c98fb63676 # v7
+        uses: peter-evans/create-pull-request@98357b18bf14b5342f975ff684046ec3b2a07725 # v8
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           commit-message: "Update registry from toolhive-registry release ${{ steps.get-release.outputs.release_tag }}"