Bump postcss-custom-properties from 12.1.8 to 12.1.10

Bumps [postcss-custom-properties](https://github.com/csstools/postcss-plugins/tree/HEAD/plugins/postcss-custom-properties) from 12.1.8 to 12.1.10.
- [Release notes](https://github.com/csstools/postcss-plugins/releases)
- [Changelog](https://github.com/csstools/postcss-plugins/blob/main/plugins/postcss-custom-properties/CHANGELOG.md)
- [Commits](https://github.com/csstools/postcss-plugins/commits/HEAD/plugins/postcss-custom-properties)

---
updated-dependencies:
- dependency-name: postcss-custom-properties
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -31,7 +31,7 @@
     "postcss-advanced-variables": "^3.0.1",
     "postcss-cli": "^10.0.0",
     "postcss-css-variables": "^0.18.0",
-    "postcss-custom-properties": "^12.1.8",
+    "postcss-custom-properties": "^12.1.10",
     "postcss-hash": "^3.0.0",
     "postcss-import": "^15.0.0",
     "postcss-mixins": "^9.0.4",