Bump postcss from 8.4.24 to 8.4.31 in /frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.24 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.4.24...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
...

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

frontend/package-lock.json

@@ -31,7 +31,7 @@
 				"minidenticons": "^4.2.0",
 				"nats.ws": "^1.16.1",
 				"numbro": "^2.3.6",
-				"postcss": "^8.4.24",
+				"postcss": "^8.4.31",
 				"prettier": "^2.8.0",
 				"prettier-plugin-svelte": "^2.8.1",
 				"svelte": "^3.54.0",
@@ -2540,9 +2540,9 @@
 			}
 		},
 		"node_modules/postcss": {
-			"version": "8.4.24",
-			"resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.24.tgz",
-			"integrity": "sha512-M0RzbcI0sO/XJNucsGjvWU9ERWxb/ytp1w6dKtxTKgixdtQDq4rmx/g8W1hnaheq9jgwL/oyEdH5Bc4WwJKMqg==",
+			"version": "8.4.31",
+			"resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
+			"integrity": "sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==",
 			"dev": true,
 			"funding": [
 				{

frontend/package.json

@@ -28,7 +28,7 @@
 		"minidenticons": "^4.2.0",
 		"nats.ws": "^1.16.1",
 		"numbro": "^2.3.6",
-		"postcss": "^8.4.24",
+		"postcss": "^8.4.31",
 		"prettier": "^2.8.0",
 		"prettier-plugin-svelte": "^2.8.1",
 		"svelte": "^3.54.0",