chore: remove trailing comma from samples package.json (googleapis#8402)

This prevents JSON parsing errors in release-please and other strict tools.

Author: suztomo

packages/google-container/samples/package.json

@@ -14,7 +14,7 @@
     "test": "mocha test --timeout 1000000"
   },
   "dependencies": {
-    "@google-cloud/container": "^6.9.0",
+    "@google-cloud/container": "^6.9.0"
   },
   "devDependencies": {
     "chai": "^4.2.0",