Bump postcss from 8.4.5 to 8.4.31 in /website

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.5 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@8.4.5...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
...

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

website/yarn.lock

@@ -6053,12 +6053,7 @@ multicast-dns@^7.2.5:
     dns-packet "^5.2.2"
     thunky "^1.0.2"
 
-nanoid@^3.1.30:
-  version "3.1.32"
-  resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.1.32.tgz#8f96069e6239cc0a9ae8c0d3b41a3b4933a88c0a"
-  integrity sha512-F8mf7R3iT9bvThBoW4tGXhXFHCctyCiUUPrWF8WaTqa3h96d9QybkSeba43XVOOE3oiLfkVDe4bT8MeGmkrTxw==
-
-nanoid@^3.3.4:
+nanoid@^3.3.6:
   version "3.3.6"
   resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.3.6.tgz#443380c856d6e9f9824267d960b4236ad583ea4c"
   integrity sha512-BGcqMMJuToF7i1rt+2PWSNVnWIkGCU78jBG3RxO/bZlnZPK2Cmi2QaffxGO/2RvWi9sL+FAiRiXMgsyxQ1DIDA==
@@ -6744,21 +6739,12 @@ postcss-zindex@^5.1.0:
   resolved "https://registry.yarnpkg.com/postcss-zindex/-/postcss-zindex-5.1.0.tgz#4a5c7e5ff1050bd4c01d95b1847dfdcc58a496ff"
   integrity sha512-fgFMf0OtVSBR1va1JNHYgMxYk73yhn/qb4uQDq1DLGYolz8gHCyr/sesEuGUaYs58E3ZJRcpoGuPVoB7Meiq9A==
 
-postcss@^8.3.11:
-  version "8.4.5"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.5.tgz#bae665764dfd4c6fcc24dc0fdf7e7aa00cc77f95"
-  integrity sha512-jBDboWM8qpaqwkMwItqTQTiFikhs/67OYVvblFFTM7MrZjt6yMKd6r2kgXizEbTTljacm4NldIlZnhbjr84QYg==
-  dependencies:
-    nanoid "^3.1.30"
-    picocolors "^1.0.0"
-    source-map-js "^1.0.1"
-
-postcss@^8.4.14, postcss@^8.4.17, 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==
+postcss@^8.3.11, postcss@^8.4.14, postcss@^8.4.17, postcss@^8.4.19:
+  version "8.4.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.31.tgz#92b451050a9f914da6755af352bdc0192508656d"
+  integrity sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==
   dependencies:
-    nanoid "^3.3.4"
+    nanoid "^3.3.6"
     picocolors "^1.0.0"
     source-map-js "^1.0.2"
 
@@ -7684,11 +7670,6 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/sort-css-media-queries/-/sort-css-media-queries-2.1.0.tgz#7c85e06f79826baabb232f5560e9745d7a78c4ce"
   integrity sha512-IeWvo8NkNiY2vVYdPa27MCQiR0MN0M80johAYFVxWWXQ44KU84WNxjslwBHmc/7ZL2ccwkM7/e6S5aiKZXm7jA==
 
-source-map-js@^1.0.1:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/source-map-js/-/source-map-js-1.0.1.tgz#a1741c131e3c77d048252adfa24e23b908670caf"
-  integrity sha512-4+TN2b3tqOCd/kaGRJ/sTYA0tR0mdXx26ipdolxcwtJVqEnqNYvlCAt1q3ypy4QMlYus+Zh34RNtYLoq2oQ4IA==
-
 source-map-js@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/source-map-js/-/source-map-js-1.0.2.tgz#adbc361d9c62df380125e7f161f71c826f1e490c"