Bump postcss in /frontend in the npm_and_yarn group across 1 directory

Bumps the npm_and_yarn group with 1 update in the /frontend directory: [postcss](https://github.com/postcss/postcss).


Updates `postcss` from 8.5.15 to 8.5.26
- [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/8.5.15...8.5.26)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.26
  dependency-type: indirect
  dependency-group: npm_and_yarn
...

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

frontend/package-lock.json

@@ -1227,9 +1227,9 @@
       "license": "MIT"
     },
     "node_modules/nanoid": {
-      "version": "3.3.14",
-      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.14.tgz",
-      "integrity": "sha512-U9kYi5bpVMEI31yC8iw4bJJp0avcHXA0W8/wNfLfnvJYzihQo2ZRPYPvpAAd570HAcCBjCTN7vnr+v4StKl1IQ==",
+      "version": "3.3.18",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.18.tgz",
+      "integrity": "sha512-DTg4MJbGMWkfi6VZFdNt2/caMbQy4Ou+Op/hJQvGEWcnVfoA1QA+xzRKAzw9jD6+GVOOeYr/mIcuDSdug6F6+w==",
       "dev": true,
       "funding": [
         {
@@ -1266,9 +1266,9 @@
       }
     },
     "node_modules/postcss": {
-      "version": "8.5.15",
-      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.15.tgz",
-      "integrity": "sha512-FfR8sjd4em2T6fb3I2MwAJU7HWVMr9zba+enmQeeWFfCbm+UOC/0X4DS8XtpUTMwWMGbjKYP7xjfNekzyGmB3A==",
+      "version": "8.5.26",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.26.tgz",
+      "integrity": "sha512-u82N74LFzG8ca+dD8puPnplTXoGH4fTPpVGuIbt36G3qvNlkvfD0lEAZSxaly3KX8TS/L1A1gsCEmvKmBcVbkQ==",
       "dev": true,
       "funding": [
         {
@@ -1286,7 +1286,7 @@
       ],
       "license": "MIT",
       "dependencies": {
-        "nanoid": "^3.3.12",
+        "nanoid": "^3.3.17",
         "picocolors": "^1.1.1",
         "source-map-js": "^1.2.1"
       },