Bump postcss-selector-parser and tailwindcss

Removes [postcss-selector-parser](https://github.com/postcss/postcss-selector-parser). It's no longer used after updating ancestor dependency [tailwindcss](https://github.com/tailwindlabs/tailwindcss/tree/HEAD/packages/tailwindcss). These dependencies need to be updated together.


Removes `postcss-selector-parser`

Updates `tailwindcss` from 3.4.0 to 4.3.3
- [Release notes](https://github.com/tailwindlabs/tailwindcss/releases)
- [Changelog](https://github.com/tailwindlabs/tailwindcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/tailwindlabs/tailwindcss/commits/v4.3.3/packages/tailwindcss)

---
updated-dependencies:
- dependency-name: postcss-selector-parser
  dependency-version:
  dependency-type: indirect
- dependency-name: tailwindcss
  dependency-version: 4.3.3
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]