Bump postcss from 8.4.38 to 8.4.39 (#391)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.38 to 8.4.39.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.38...8.4.39)

---
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

@@ -19,7 +19,7 @@
     "eslint-plugin-svelte": "^2.39.4",
     "mdi-svelte": "^1.1.2",
     "obs-websocket-js": "^5.0.1",
-    "postcss": "^8.4.38",
+    "postcss": "^8.4.39",
     "rollup": "^4",
     "rollup-plugin-livereload": "^2.0.5",
     "rollup-plugin-polyfill-node": "^0.13.0",