chore(deps-dev): bump postcss from 8.4.8 to 8.4.12 (mermaid-js#704)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.8 to 8.4.12.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.8...8.4.12)

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

package.json

@@ -38,7 +38,7 @@
 		"lint-staged": "^12.3.7",
 		"mocha": "^9.2.2",
 		"node-html-parser": "^5.3.3",
-		"postcss": "^8.4.8",
+		"postcss": "^8.4.12",
 		"postcss-load-config": "^3.1.3",
 		"prettier": "~2.6.0",
 		"prettier-plugin-svelte": "^2.6.0",

yarn.lock

@@ -3768,10 +3768,10 @@ postcss-value-parser@^4.1.0, postcss-value-parser@^4.2.0:
   resolved "https://registry.yarnpkg.com/postcss-value-parser/-/postcss-value-parser-4.2.0.tgz#723c09920836ba6d3e5af019f92bc0971c02e514"
   integrity sha512-1NNCs6uurfkVbeXG4S8JFT9t19m45ICnif8zWLd5oPSZ50QnwMfK+H3jv408d4jw/7Bttv5axS5IiHoLaVNHeQ==
 
-postcss@^8.3.0, postcss@^8.4.4, postcss@^8.4.6, postcss@^8.4.8:
-  version "8.4.8"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.8.tgz#dad963a76e82c081a0657d3a2f3602ce10c2e032"
-  integrity sha512-2tXEqGxrjvAO6U+CJzDL2Fk2kPHTv1jQsYkSoMeOis2SsYaXRO2COxTdQp99cYvif9JTXaAk9lYGc3VhJt7JPQ==
+postcss@^8.3.0, postcss@^8.4.12, postcss@^8.4.4, postcss@^8.4.6:
+  version "8.4.12"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.12.tgz#1e7de78733b28970fa4743f7da6f3763648b1905"
+  integrity sha512-lg6eITwYe9v6Hr5CncVbK70SoioNQIq81nsaG86ev5hAidQvmOeETBqs7jm43K2F5/Ley3ytDtriImV6TpNiSg==
   dependencies:
     nanoid "^3.3.1"
     picocolors "^1.0.0"