Shrink flake-updating action (#193)

.github/workflows/flake_update.yaml

@@ -2,6 +2,8 @@
 name: Weekly Nix Flake Update
 
 on:
+  pull_request:
+    branches: [ main ]
   schedule:
     - cron: '0 0 * * 0'  # Runs at 00:00 every Sunday
   workflow_dispatch:  # Allows manual triggering
@@ -41,15 +43,12 @@ jobs:
           app-id: ${{ secrets.APP_ID }}
           private-key: ${{ secrets.APP_PRIVATE_KEY }}
 
-      - name: Prepare to create commit
-        run: python -m venv /tmp/venv && /tmp/venv/bin/python -m pip install -r .github/workflows/requirements.txt
-
-      - name: Create pull request
+      - name: Raise pull request
+        uses: Smaug123/commit-action@cc25e6d80a796c49669dda4a0aa36c54c573983d
         id: cpr
-        env:
-            DEFAULT_BRANCH: ${{ github.event.repository.default_branch }}
-            BEARER_TOKEN: ${{ steps.generate-token.outputs.token }}
-        run: /tmp/venv/bin/python .github/workflows/commit.py
+        with:
+            bearer-token: ${{ steps.generate-token.outputs.token }}
+            pr-title: "Upgrade Nix flake and deps"
 
       - name: Enable Pull Request Automerge
         if: ${{ steps.cpr.outputs.pull-request-number }}