gh: manifest: Point to a PR

Work in progress.

Signed-off-by: Carles Cufi <[email protected]>

Author: carlescufi

.github/workflows/manifest.yml

@@ -26,11 +26,12 @@ jobs:
           west init -l . || true
 
       - name: Manifest
-        uses: zephyrproject-rtos/[email protected]
+        uses: zephyrproject-rtos/action-manifest@main
+        working-directory: zephyrproject/zephyr
         with:
           github-token: ${{ secrets.ZB_GITHUB_TOKEN }}
           manifest-path: 'west.yml'
-          checkout-path: 'zephyrproject/zephyr'
+          checkout-path: '.'
           use-tree-checkout: 'true'
           check-impostor-commits: 'true'
           label-prefix: 'manifest-'