fix the secret name. Add missing versions part.

Author: yuri-sergiichuk

cloudbuild.yaml

@@ -50,5 +50,5 @@ substitutions:
   _SERVICE_NAME: "chat-bot-server"
 availableSecrets:
   secretManager:
-    - versionName: "projects/${PROJECT_ID}/secrets/GithubToken/latest"
+    - versionName: "projects/${PROJECT_ID}/secrets/GithubToken/versions/latest"
       env: "GITHUB_TOKEN"