changed workflows solana yml

Author: Bengt Lofgren

.github/workflows/solana.yml

@@ -4,7 +4,10 @@ on:
   push:
     branches:
       - main
-  pull_request: 
+  pull_request:
+    branches:
+      - main
+      - 'shim/integration'
     paths:
       - 'solana/**'