Stop using xtask for clippy (#13223)

This fixes an extra 10 second delay when needing to recompile xtask, and
allows passing arbitrary clippy args (like --allow-dirty)

Release Notes:

- N/A

.github/workflows/deploy_collab.yml

@@ -27,7 +27,7 @@ jobs:
         uses: ./.github/actions/check_style
 
       - name: Run clippy
-        run: cargo xtask clippy
+        run: ./script/clippy
 
   tests:
     name: Run tests