Problem/Motivation
Stylelint updated to 15 #3344087: Update Stylelint and Prettier for Drupal 10.1 and use Prettier for formatting PostCSS
But seems we ignore its `Significant changes`:
https://stylelint.io/migration-guide/to-15#significant-changes
Now stylelint only cares about `Code-quality rules` and never cares about `Formatting rules`
That formatting rules removed from our base config
`Removed: 64 rules deprecated in stylelint@15.0.0. For details, see the migration guide.`
https://github.com/stylelint/stylelint-config-standard/blob/main/CHANGEL...
More info: https://prettier.io/docs/en/comparison
Steps to reproduce
Put any bad formatted postcss into any core pipeline and it pass all checkings
Proposed resolution
Use https://github.com/prettier/stylelint-prettier
3 MRs here
1. `proof-of-failures ` explains that after upgrade we don't have formatting errors reported. I downgraded stylelint and got pipeline reports about formatting errors which younger than 14-15 stylelint upgrade (UPD + new max-line-length recently removed)
2. `success-on-anything` explains why this ticket is major. Right now any unformatted postcss can appears in core without pipeline reports
3. `3409048-postcss-file-formatting` Fix MR. With stylelint-prettier. We need to add result of command `yarn lint:css --fix` here and commit.