gha: update from 5.0.0~beta1 to 5.0.x

Author: MisterDA

.github/workflows/main.yml

@@ -15,7 +15,7 @@ jobs:
           - ubuntu-latest
           - macos-latest
         ocaml-compiler:
-          - ocaml-base-compiler.5.0.0~beta1
+          - ocaml-base-compiler.5.0.x
           - ocaml-variants.5.1.0+trunk
 
     runs-on: ${{ matrix.os }}