remove containers line, only run on prs

.github/workflows/check-swig.yml

@@ -1,15 +1,13 @@
 name: Checks - swig
 
 on:
-  push:
   pull_request:
   workflow_dispatch:
 
 jobs:
   swig:
     runs-on: ubuntu-latest
-    # container:
-      # image: ghcr.io/llnl/sundials_spack_cache:llvm-17.0.4-h4lflucc3v2vage45opbo2didtcuigsn.spack
+
     steps:
       - name: Install git
         run: |