chore(deps): update peter-evans/create-pull-request action to v8

Author: renovate[bot]

.github/workflows/update.yml

@@ -32,7 +32,7 @@ jobs:
       - run: nix flake check --keep-going --accept-flake-config --show-trace
       - name: Create Pull Request
         id: create-pull-request
-        uses: peter-evans/create-pull-request@v7
+        uses: peter-evans/create-pull-request@v8
         with:
           commit-message: Update Python versions
           title: Update Python versions