chore(deps-dev): bump postcss-loader from 7.3.3 to 8.0.0

Bumps [postcss-loader](https://github.com/webpack-contrib/postcss-loader) from 7.3.3 to 8.0.0.
- [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@v7.3.3...v8.0.0)

---
updated-dependencies:
- dependency-name: postcss-loader
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

package.json

@@ -59,7 +59,7 @@
     "karma-jasmine-html-reporter": "~2.1.0",
     "ngx-build-plus": "^14.0.0",
     "postcss-import": "^15.1.0",
-    "postcss-loader": "^7.3.3",
+    "postcss-loader": "^8.0.0",
     "postcss-scss": "^4.0.9",
     "prettier": "^2.8.8",
     "prettier-plugin-organize-attributes": "^0.0.5",