fix(ci): resolve v4 CI timeout by disabling Nx Cloud distributed execution (#9623)

Author: joseph0926

.github/workflows/pr.yml

@@ -8,8 +8,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  NX_CLOUD_DISTRIBUTED_EXECUTION: true
-  NX_CLOUD_DISTRIBUTED_EXECUTION_AGENT_COUNT: 3
+  NX_CLOUD_DISTRIBUTED_EXECUTION: false
   NX_CLOUD_ACCESS_TOKEN: ${{ secrets.NX_CLOUD_ACCESS_TOKEN }}
   NX_CLOUD_AUTH_TOKEN: ${{ secrets.NX_CLOUD_AUTH_TOKEN }}