up-to-date checking on npm-based steps is too generous

If you are submitting a **bug**, please include the following:

- [x] summary of problem

The npm-based steps don't capture their settings files in their state, which makes them too generous in claiming to be up-to-date. This applies to:

- `ESLintFormatterStep`
- `PrettierFormatterStep`
- `TsFmtFormatterStep`.

This bug was introduced in #2135 as part of the effort to make all steps roundtrip-serializable for Gradle.

- [x] spotless version
plugin-gradle 7.0, plugin-maven 3.0