fix(deps): update dependency purgecss-webpack-plugin to v6

package.json

@@ -11,7 +11,7 @@
     "jquery": "3.7.1",
     "mini-css-extract-plugin": "2.7.7",
     "open-iconic": "1.1.1",
-    "purgecss-webpack-plugin": "5.0.0",
+    "purgecss-webpack-plugin": "6.0.0",
     "webpack": "latest",
     "webpack-cli": "latest",
     "webpack-subresource-integrity": "5.1.0"