actions: manifest: switch to PR #15 and remove ref: line in checkout

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

Author: carlescufi

.github/workflows/manifest.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           path: zephyrproject/zephyr
-          ref: ${{ github.event.pull_request.head.sha }}
+          #ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
           persist-credentials: false
 
@@ -31,7 +31,7 @@ jobs:
           west init -l . || true
 
       - name: Manifest
-        uses: zephyrproject-rtos/action-manifest@1729cded3fc798cf0de4a789c596dcb9c40eb14c # v1.9.1
+        uses: zephyrproject-rtos/action-manifest@pull/25/head
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           manifest-path: 'west.yml'