disable pr action and enable fail fast

.github/workflows/main.yml

@@ -4,15 +4,15 @@ name: hdf5 dev CI
 on:
   push:
     branches: [ develop, hdf5_1_12, hdf5_1_10, hdf5_1_8 ]
-  pull_request:
-    branches: [ develop ]
+#  pull_request:
+#    branches: [ develop ]
 
 # A workflow run is made up of one or more jobs that can run sequentially or in parallel
 jobs:
   # This workflow contains a single job called "build"
   build:
     strategy:
-      fail-fast: false
+#      fail-fast: false
       matrix:
         name: ["Windows Latest MSVC", "Ubuntu Latest GCC", "macOS Latest Clang"]
         include: