chore(repo): add nightly builds to prs

Author: mrcnk

.github/workflows/ci.yml

@@ -2,6 +2,8 @@ name: MinaJS Continuous Integration
 on:
   push:
     branches: [main]
+  pull_request:
+    branches: [main]
 jobs:
   test_and_release:
     name: Test and release