Bump postcss-loader from 7.3.4 to 8.2.0 in /packages/block-editor-tools

Bumps [postcss-loader](https://github.com/webpack-contrib/postcss-loader) from 7.3.4 to 8.2.0.
- [Release notes](https://github.com/webpack-contrib/postcss-loader/releases)
- [Changelog](https://github.com/webpack-contrib/postcss-loader/blob/master/CHANGELOG.md)
- [Commits](webpack/postcss-loader@v7.3.4...v8.2.0)

---
updated-dependencies:
- dependency-name: postcss-loader
  dependency-version: 8.2.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

packages/block-editor-tools/package.json

@@ -69,7 +69,7 @@
     "css-loader": "^6.8.1",
     "dompurify": "^3.0.6",
     "papaparse": "^5.4.1",
-    "postcss-loader": "^7.3.3",
+    "postcss-loader": "^8.2.0",
     "prop-types": "^15.8.1",
     "resolve-url-loader": "^5.0.0",
     "sass": "^1.69.5",