build: Bump postcss in /nova-components/WaitingListsManager (#3221)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.27 to 8.4.29.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.27...8.4.29)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Calum Towers <[email protected]>

nova-components/WaitingListsManager/yarn.lock

@@ -4324,9 +4324,9 @@ postcss@^7.0.36:
     supports-color "^6.1.0"
 
 postcss@^8.1.10, postcss@^8.2.15, postcss@^8.4, postcss@^8.4.14:
-  version "8.4.27"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.27.tgz#234d7e4b72e34ba5a92c29636734349e0d9c3057"
-  integrity sha512-gY/ACJtJPSmUFPDCHtX78+01fHa64FaU4zaaWfuh1MhGJISufJAH4cun6k/8fwsHYeK4UQmENQK+tRLCFJE8JQ==
+  version "8.4.29"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.29.tgz#33bc121cf3b3688d4ddef50be869b2a54185a1dd"
+  integrity sha512-cbI+jaqIeu/VGqXEarWkRCCffhjgXc0qjBtXpqJhTBohMUjUQnbBr0xqX3vEKudc4iviTewcJo5ajcec5+wdJw==
   dependencies:
     nanoid "^3.3.6"
     picocolors "^1.0.0"