Enable cross-compiler tests on pushes and pull requests

Author: shym

.github/workflows/build-cross.yml

@@ -1,9 +1,8 @@
 name: Cross compilers
 
 on:
+  push:
   pull_request:
-    types: [opened, synchronize, reopened, labeled, unlabeled]
-  workflow_dispatch:
 
 # Restrict the GITHUB_TOKEN
 permissions: {}
@@ -36,7 +35,6 @@ env:
 
 jobs:
   non-cross:
-    if: contains(github.event.pull_request.labels.*.name, 'run-crosscompiler-tests')
     runs-on: ubuntu-latest
     steps:
       - name: Checkout OCaml