Remove deprecated stylelint rules which are handled by prettier (#24767)

.stylelintrc.js

@@ -1,4 +1,4 @@
 module.exports = {
     ...require("matrix-react-sdk/.stylelintrc.js"),
-    extends: ["stylelint-config-standard", "stylelint-config-prettier"],
+    extends: ["stylelint-config-standard"],
 };

package.json

@@ -167,7 +167,6 @@
         "string-replace-loader": "3",
         "style-loader": "2",
         "stylelint": "^15.0.0",
-        "stylelint-config-prettier": "^9.0.4",
         "stylelint-config-standard": "^30.0.0",
         "stylelint-scss": "^4.2.0",
         "terser-webpack-plugin": "^4.0.0",