Bump postcss from 8.3.11 to 8.4.7

Bumps [postcss](https://github.com/postcss/postcss) from 8.3.11 to 8.4.7.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.3.11...8.4.7)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -45,7 +45,7 @@
         "history": "^4.10.1",
         "jasmine-ts": "^0.4.0",
         "jest": "^27.3.1",
-        "postcss": "^8.3.11",
+        "postcss": "^8.4.7",
         "tailwindcss": "^2.2.19",
         "ts-jest": "^27.0.7",
         "typescript": "^4.5.2",