turn off nighlty on PR, add back normal on PR

Author: clee2000

.github/workflows/build-tutorials-nightly.yml

@@ -1,7 +1,8 @@
-name: Build tutorials against nightly or test
+name: Build tutorials (nightly/test)
 
 on:
-  pull_request:
+  # Only main branch for now
+  # pull_request:
   push:
     branches:
       - main

.github/workflows/build-tutorials.yml

@@ -1,7 +1,7 @@
 name: Build tutorials
 
 on:
-  # pull_request:
+  pull_request:
   push:
     branches:
       - main