🛠️update csstree top 2.3.1

Author: Bart Veneman

package-lock.json

@@ -43,7 +43,7 @@
   ],
   "dependencies": {
     "@bramus/specificity": "^2.2.0",
-    "css-tree": "2.2.1"
+    "css-tree": "^2.3.1"
   },
   "devDependencies": {
     "microbundle": "^0.15.1",