Fix false positives for multiple pseudo-class in selector-pseudo-class-no-unknown

[Mottie]

Describe the issue. Is it a bug or a feature request (new rule, new option, etc.)?

When multiple pseudoclasses (chained) are added to the webkit scrollbar selector, we see a "selector-pseudo-class-no-unknown" error. In this example css:

::-webkit-scrollbar-button:horizontal:decrement {
  background-color: transparent;
}

::-webkit-scrollbar-button:decrement:horizontal {
  background-color: transparent;
}

::-webkit-scrollbar-button:horizontal {
  background-color: transparent;
}

::-webkit-scrollbar-button:decrement {
  background-color: transparent;
}

The first two selectors show the error:

1:38 error Unexpected unknown pseudo-class selector ":decrement" (selector-pseudo-class-no-unknown)
5:37 error Unexpected unknown pseudo-class selector ":horizontal" (selector-pseudo-class-no-unknown)

The standard stylelint configuration is being used, and the error can be seen after entering the above css into the main stylelint demo.

Which version of stylelint are you using?

8.0.0

How are you running stylelint: CLI, PostCSS plugin, Node API?

Reproducible in the online demo

Does your issue relate to non-standard syntax (e.g. SCSS, nesting, etc.)?

No

What did you expect to happen?

No "selector-pseudo-class-no-unknown" error.

What actually happened (e.g. what warnings or errors you are getting)?

"selector-pseudo-class-no-unknown" error.

[alexander-akait]

@Mottie thanks for issue, seems it is bug

[ntwb]

Fixed via 982024d