Bump postcss from 8.2.7 to 8.2.10 in /webpack

Bumps [postcss](https://github.com/postcss/postcss) from 8.2.7 to 8.2.10.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.2.7...8.2.10)

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

Author: dependabot[bot]

webpack/package-lock.json

@@ -17,7 +17,7 @@
     "file-loader": "^6.2.0",
     "mini-css-extract-plugin": "^1.3.9",
     "node-sass": "^5.0.0",
-    "postcss": "^8.2.7",
+    "postcss": "^8.2.10",
     "postcss-loader": "^5.1.0",
     "sass-loader": "^11.0.1",
     "style-loader": "^2.0.0",