CI: Add --auto-accept for west blobs fetch command

Add `--auto-accept` option to suppress interactive prompt
when fetching blobs.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>

Author: soburi

.github/workflows/build.yml

@@ -37,7 +37,7 @@ jobs:
 
       - name: Initialize
         run: |
-          west blobs fetch arduinocore-zephyr
+          west blobs --auto-accept fetch arduinocore-zephyr
 
       - name: Setup Rust toolchain
         run: |