ci(samples): Check out the default ref without submodules in the Samples workflow

The head-SHA ref only matters for build.yml's snapshot upload, and the
repository has had no submodules since #3189.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: runningcode

.github/workflows/samples.yml

@@ -26,9 +26,6 @@ jobs:
     steps:
       - name: Checkout Repo
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
-          submodules: 'recursive'
 
       - name: Setup Java Version
         uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0