Bump postcss from 8.5.5 to 8.5.6 in the postcss group

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


Updates `postcss` from 8.5.5 to 8.5.6
- [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/8.5.5...8.5.6)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.6
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: postcss
...

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

package-lock.json

@@ -18599,9 +18599,9 @@
       }
     },
     "node_modules/postcss": {
-      "version": "8.5.5",
+      "version": "8.5.6",
-      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.5.tgz",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.6.tgz",
-      "integrity": "sha512-d/jtm+rdNT8tpXuHY5MMtcbJFBkhXE6593XVR9UoGCH8jSFGci7jGvMGH5RYd5PBJW+00NZQt6gf7CbagJCrhg==",
+      "integrity": "sha512-3Ybi1tAuwAP9s0r1UQ2J4n5Y0G05bJkpUIO0/bI9MhwmD70S5aTWbXGBwxHrelT+XM1k6dM0pk+SwNkpTRN7Pg==",
       "funding": [
         {
           "type": "opencollective",