Bump postcss, autoprefixer, css-loader, optimize-css-assets-webpack-p…

…lugin, postcss-loader and postcss-rtl

Bumps [postcss](https://github.com/postcss/postcss) to 8.4.31 and updates ancestor dependencies [postcss](https://github.com/postcss/postcss), [autoprefixer](https://github.com/postcss/autoprefixer), [css-loader](https://github.com/webpack-contrib/css-loader), [optimize-css-assets-webpack-plugin](https://github.com/NMFR/optimize-css-assets-webpack-plugin), [postcss-loader](https://github.com/webpack-contrib/postcss-loader) and [postcss-rtl](https://github.com/vkalinichev/postcss-rtl). These dependencies need to be updated together.


Updates `postcss` from 6.0.23 to 8.4.31
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@6.0.23...8.4.31)

Updates `autoprefixer` from 9.8.8 to 10.4.16
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/main/CHANGELOG.md)
- [Commits](postcss/autoprefixer@9.8.8...10.4.16)

Updates `css-loader` from 2.1.1 to 6.8.1
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/css-loader@v2.1.1...v6.8.1)

Updates `optimize-css-assets-webpack-plugin` from 5.0.8 to 6.0.1
- [Commits](NMFR/optimize-css-assets-webpack-plugin@v5.0.8...v6.0.1)

Updates `postcss-loader` from 3.0.0 to 7.3.3
- [Release notes](https://github.com/webpack-contrib/postcss-loader/releases)
- [Changelog](https://github.com/webpack-contrib/postcss-loader/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/postcss-loader@v3.0.0...v7.3.3)

Updates `postcss-rtl` from 1.7.3 to 2.0.0
- [Release notes](https://github.com/vkalinichev/postcss-rtl/releases)
- [Changelog](https://github.com/vkalinichev/postcss-rtl/blob/master/CHANGELOG.md)
- [Commits](vkalinichev/postcss-rtl@v1.7.3...v2.0.0)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
- dependency-name: autoprefixer
  dependency-type: direct:development
- dependency-name: css-loader
  dependency-type: direct:development
- dependency-name: optimize-css-assets-webpack-plugin
  dependency-type: direct:development
- dependency-name: postcss-loader
  dependency-type: direct:development
- dependency-name: postcss-rtl
  dependency-type: direct:development
...

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