chore(deps-dev): bump postcss from 8.5.10 to 8.5.12 (#987)

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.10 to 8.5.12.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.10...8.5.12)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.12
  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-lock.json

@@ -60,7 +60,7 @@
     "mkdirp": "^3.0.1",
     "ordered-read-streams": "^2.0.0",
     "plugin-error": "^2.0.1",
-    "postcss": "^8.5.10",
+    "postcss": "^8.5.12",
     "postcss-calc": "^10.1.1",
     "postcss-custom-properties": "^15.0.1",
     "postcss-import": "^16.1.1",