ci: Disable NCS manifest PR creation for upstream PRs

For PRs updating the FW blobs for upstream, the manifest PR in NCS is
not needed, so, disable this action.

Signed-off-by: Chaitanya Tata <[email protected]>

Author: krish2718

.github/workflows/manifest-PR.yml

@@ -4,7 +4,8 @@ on:
     types: [opened, synchronize, closed]
     branches:
       - main
-
+    paths-ignore:
+      - 'nrf_wifi/bin/zephyr/**'
 
 jobs:
   call-manifest-pr-action: