chore: Track the entire agentplatform folder in noxfile LINT_PATHS.

PiperOrigin-RevId: 924566890

Author: vertex-sdk-bot

noxfile.py

@@ -34,7 +34,7 @@
     "docs",
     "google",
     "vertexai",
-    "agentplatform/_genai",
+    "agentplatform",
     "noxfile.py",
     "setup.py",
 ]