Bump postcss from 8.2.10 to 8.2.13

Bumps [postcss](https://github.com/postcss/postcss) from 8.2.10 to 8.2.13.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.2.10...8.2.13)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:production
...

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

package.json

@@ -12,6 +12,6 @@
   },
   "dependencies": {
     "merge": "2.1.1",
-    "postcss": "8.2.10"
+    "postcss": "8.2.13"
   }
 }