action: update to PR 15

And set import flags.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

Author: carlescufi

.github/workflows/manifest.yml

@@ -26,12 +26,13 @@ jobs:
           west init -l . || true
 
       - name: Manifest
-        uses: zephyrproject-rtos/action-manifest@pull/14/head
+        uses: zephyrproject-rtos/action-manifest@pull/15/head
         with:
           github-token: ${{ secrets.ZB_GITHUB_TOKEN }}
           manifest-path: 'west.yml'
           checkout-path: 'zephyrproject/zephyr'
           use-tree-checkout: 'true'
+          west-import-flag: 'none'
           check-impostor-commits: 'true'
           label-prefix: 'manifest-'
           verbosity-level: '1'