Bump create-pull-request to v8 (Node 24)

Clears the last Node.js 20 deprecation in the Co-op Translator workflow.
v8 only changes the action runtime to Node 24; no input changes.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: DanWahlin

.github/workflows/co-op-translator.yml

@@ -108,7 +108,7 @@ jobs:
           if-no-files-found: ignore
 
       - name: Create pull request
-        uses: peter-evans/create-pull-request@v7
+        uses: peter-evans/create-pull-request@v8
         with:
           token: ${{ secrets.GH_AW_GITHUB_TOKEN }}
           commit-message: "Update translations via Co-op Translator"