fix: use system token in release workflow

.github/workflows/agent-marketplace-release.yaml

@@ -66,10 +66,6 @@ on:
         required: false
         type: string
         default: marketplace
-    secrets:
-      GITHUB_TOKEN:
-        required: false
-
 permissions:
   contents: write
   pull-requests: write
@@ -90,7 +86,7 @@ jobs:
         id: release
         uses: googleapis/release-please-action@v4
         with:
-          token: ${{ secrets.GITHUB_TOKEN || github.token }}
+          token: ${{ github.token }}
           target-branch: ${{ github.event.repository.default_branch || 'master' }}
           config-file: ${{ inputs.release_config_file }}
           manifest-file: ${{ inputs.release_manifest_file }}