alternative way to check if file is executable

just fyi this might be another way (better? dunno)

https://stackoverflow.com/a/41929624/1223975

```js
const fs = require('fs');

fs.access('./foobar.sh', fs.constants.X_OK, (err) => {
console.log(err ? 'cannot execute' : 'can execute');
});
```

Review the linked Stack Overflow example and compare its fs.access(..., fs.constants.X_OK, ...) behavior with the repository's current executable check. Decide whether the alternative should replace the existing approach, then add or update coverage for the chosen behavior.

Written by the indexing model from the issue text.