Spotless fails to format .gitignore

Hello :wave:,

I was trying out Spotless for Gradle today and found that if failed to format my .gitignore. A minimal example would use the following `build.gradle`:

```
plugins {
id "com.diffplug.spotless" version "6.3.0"
}

spotless {
format 'misc', {
target '.gitignore'
trimTrailingWhitespace()
indentWithTabs()
endWithNewline()
}
}
```

Then introduce any formatting violation in `.gitignore` and the `spotlessCheck`, `spotlessApply`, `spotlessMiscCheck` etc. don't pick it up. Any other filename appears to work fine.

Spotless 6.3.0
Gradle 7.4.1
Java 11 and 17
Linux and macOS