chore(deps): bump postcss from 7.0.34 to 8.0.7

Bumps [postcss](https://github.com/postcss/postcss) from 7.0.34 to 8.0.7.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/master/CHANGELOG.md)
- [Commits](postcss/postcss@7.0.34...8.0.7)

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

package.json

@@ -33,7 +33,7 @@
   "dependencies": {
     "autoprefixer": "^9.4.3",
     "micromatch": "^4.0.2",
-    "postcss": "^7.0.7"
+    "postcss": "^8.0.7"
   },
   "devDependencies": {
     "chai": "^4.2.0",