"Project Checks whitespace error" check is not particularly helpful

### Description

Sometimes, you will get a fail on the CI from project checks complaining that `FAIL - has whitespace errors. See `git show --check 30bfe29f9810b8c743a6068dd30e61398785f1ed`.`

But then, it does not say what is a whitespace error, where that would be, why any of it is actually bad, and most importantly:
```
git show --check 30bfe29f9810b8c743a6068dd30e61398785f1ed
fatal: bad object 30bfe29f9810b8c743a6068dd30e61398785f1ed
```

So:
- is this check serving a purpose? is it useful in any way? what exactly is it doing? what is it complaining about?
- if yes to the above, we should fix it so that it does provide usable / actionable feedback

### Steps to reproduce the issue

na

### Describe the results you received and expected

na

### What version of nerdctl are you using?

main

### Are you using a variant of nerdctl? (e.g., Rancher Desktop)

None

### Host information

_No response_