Fix for issue 4313 selector list not expanding

[puckowski]

What:

PR contains a fix for issue #4313 selector list not expanding with & symbol.

Why:

In Less.js version 4.2.2, this Less:

.broken {
  &:not(&--a, &--b):hover {
    background-color: green;
  }
}

produces the incorrect CSS:

.broken:not(&--a, &--b):hover {
  background-color: green;
}

the & symbol should now be properly expanded with the fix.

Checklist:

• [ ] Documentation
• [x] Added/updated unit tests
• [x] Code complete

[puckowski]

Looks like CI may have an issue. Tests pass locally for me.

browserType.launch: Executable doesn't exist at /home/runner/.cache/ms-playwright/chromium_headless_shell-1148/chrome-linux/headless_shell
╔═════════════════════════════════════════════════════════════════════════╗
║ Looks like Playwright Test or Playwright was just installed or updated. ║
║ Please run the following command to download new browsers:              ║
║                                                                         ║
║     npx playwright install                                              ║
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║ <3 Playwright Team                                                      ║
╚═════════════════════════════════════════════════════════════════════════╝

[puckowski]

I re-ran CI but ran into issues. Branch passes all tests locally for me. I wouldn't expect files changed to impact CI (two test files, one source file). Would you be able to take a look? @iChenLei

[puckowski]

FYI figured out the new CI issue. Had to revise CI file to pin Playwright version to resolve browser binary mismatches. @iChenLei @matthew-dean

See files changed in this PR.

[puckowski]

PR was updated and is now more narrow in scope. Let me know if you have an opportunity to review. @matthew-dean