Bump postcss from 8.4.18 to 8.4.21 (#2393)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.18 to 8.4.21.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.18...8.4.21)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

package.json

@@ -64,7 +64,7 @@
     "globby": "13.1.3",
     "jest": "29.3.1",
     "js-yaml": "4.1.0",
-    "postcss": "8.4.18",
+    "postcss": "8.4.21",
     "postcss-calc": "8.2.4",
     "postcss-import": "15.0.0",
     "postcss-load-config": "4.0.1",

yarn.lock

@@ -4735,19 +4735,10 @@ postcss-value-parser@^4.0.0, postcss-value-parser@^4.0.2, postcss-value-parser@^
   resolved "https://registry.yarnpkg.com/postcss-value-parser/-/postcss-value-parser-4.2.0.tgz#723c09920836ba6d3e5af019f92bc0971c02e514"
   integrity sha512-1NNCs6uurfkVbeXG4S8JFT9t19m45ICnif8zWLd5oPSZ50QnwMfK+H3jv408d4jw/7Bttv5axS5IiHoLaVNHeQ==
 
-postcss@8.4.18:
-  version "8.4.18"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.18.tgz#6d50046ea7d3d66a85e0e782074e7203bc7fbca2"
-  integrity sha512-Wi8mWhncLJm11GATDaQKobXSNEYGUHeQLiQqDFG1qQ5UTDPTEvKw0Xt5NsTpktGTwLps3ByrWsBrG0rB8YQ9oA==
-  dependencies:
-    nanoid "^3.3.4"
-    picocolors "^1.0.0"
-    source-map-js "^1.0.2"
-
-postcss@^8.1.0, postcss@^8.1.4, postcss@^8.2.4, postcss@^8.3.11, postcss@^8.3.6, postcss@^8.4.19:
-  version "8.4.19"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.19.tgz#61178e2add236b17351897c8bcc0b4c8ecab56fc"
-  integrity sha512-h+pbPsyhlYj6N2ozBmHhHrs9DzGmbaarbLvWipMRO7RLS+v4onj26MPFXA5OBYFxyqYhUJK456SwDcY9H2/zsA==
+postcss@8.4.21, postcss@^8.1.0, postcss@^8.1.4, postcss@^8.2.4, postcss@^8.3.11, postcss@^8.3.6, postcss@^8.4.19:
+  version "8.4.21"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.21.tgz#c639b719a57efc3187b13a1d765675485f4134f4"
+  integrity sha512-tP7u/Sn/dVxK2NnruI4H9BG+x+Wxz6oeZ1cJ8P6G/PZY0IKk4k/63TDsQf2kQq3+qoJeLm2kIBUNlZe3zgb4Zg==
   dependencies:
     nanoid "^3.3.4"
     picocolors "^1.0.0"