fix(deps): update dependency postcss-rtlcss to v5.6.1

Author: renovate[bot]

package-lock.json

@@ -84,7 +84,7 @@
     "postcss": "8.4.49",
     "postcss-custom-media": "10.0.8",
     "postcss-loader": "7.3.4",
-    "postcss-rtlcss": "5.1.2",
+    "postcss-rtlcss": "5.6.1",
     "react-dev-utils": "12.0.1",
     "react-refresh": "0.16.0",
     "resolve-url-loader": "5.0.0",