Bump postcss from 8.4.29 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.29 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.29...8.4.31)

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

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -157,7 +157,7 @@
         "modernizr": "^3.12.0",
         "node-fetch": "^2.6.7",
         "optimize-css-assets-webpack-plugin": "^6.0.0",
-        "postcss": "^8.4.16",
+        "postcss": "^8.4.31",
         "postcss-easings": "^2.0.0",
         "postcss-hexrgba": "2.0.1",
         "postcss-import": "^12.0.1",

yarn.lock

@@ -10896,10 +10896,10 @@ postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.14, postcss@^7.0.17, postcss@^7.0.1
     picocolors "^0.2.1"
     source-map "^0.6.1"
 
-postcss@^8.2.1, postcss@^8.3.11, postcss@^8.4.16, postcss@^8.4.27:
-  version "8.4.29"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.29.tgz#33bc121cf3b3688d4ddef50be869b2a54185a1dd"
-  integrity sha512-cbI+jaqIeu/VGqXEarWkRCCffhjgXc0qjBtXpqJhTBohMUjUQnbBr0xqX3vEKudc4iviTewcJo5ajcec5+wdJw==
+postcss@^8.2.1, postcss@^8.3.11, postcss@^8.4.27, postcss@^8.4.31:
+  version "8.4.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.31.tgz#92b451050a9f914da6755af352bdc0192508656d"
+  integrity sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==
   dependencies:
     nanoid "^3.3.6"
     picocolors "^1.0.0"