Bump postcss from 8.4.30 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.30 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@8.4.30...8.4.31)

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

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

package.json

@@ -43,7 +43,7 @@
 		"cssnano-preset-advanced": "6.0.1",
 		"dotenv": "16.3.1",
 		"firebase": "10.4.0",
-		"postcss": "8.4.30",
+		"postcss": "8.4.31",
 		"postcss-combine-duplicated-selectors": "10.0.3",
 		"postcss-combine-media-query": "1.0.1",
 		"postcss-import": "15.1.0",