ci: sync nitpick workflow

Committed via https://github.com/asottile/all-repos

Author: linuxdaemon

.github/workflows/nitpick.yml

@@ -15,11 +15,8 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
 
-      - name: Set up Python
-        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
-        with:
-          python-version: '3.x'
-          cache: 'pip'
+      - name: Install nitpick
+        run: pipx install nitpick
 
       - name: Run nitpick
         run: nitpick fix || true