deps: bump the dependency-updates group with 2 updates

Bumps the dependency-updates group with 2 updates: [postcss](https://github.com/postcss/postcss) and [eslint-plugin-prettier](https://github.com/prettier/eslint-plugin-prettier).


Updates `postcss` from 8.5.3 to 8.5.4
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.3...8.5.4)

Updates `eslint-plugin-prettier` from 5.4.0 to 5.4.1
- [Release notes](https://github.com/prettier/eslint-plugin-prettier/releases)
- [Changelog](https://github.com/prettier/eslint-plugin-prettier/blob/main/CHANGELOG.md)
- [Commits](prettier/eslint-plugin-prettier@v5.4.0...v5.4.1)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dependency-updates
- dependency-name: eslint-plugin-prettier
  dependency-version: 5.4.1
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: dependency-updates
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]