Fix: Remove unminified UMD and tighten size-limit thresholds

- Remove dist/react-final-form-arrays.umd.js (unminified)
- Tighten limits: 2kB for minified, 3kB for es/cjs

Per CodeRabbit review feedback.

Author: Erik Rasmussen

package.json

@@ -113,19 +113,15 @@
   "size-limit": [
     {
       "path": "dist/react-final-form-arrays.umd.min.js",
-      "limit": "4kB"
-    },
-    {
-      "path": "dist/react-final-form-arrays.umd.js",
-      "limit": "4kB"
+      "limit": "2kB"
     },
     {
       "path": "dist/react-final-form-arrays.es.js",
-      "limit": "4kB"
+      "limit": "3kB"
     },
     {
       "path": "dist/react-final-form-arrays.cjs.js",
-      "limit": "4kB"
+      "limit": "3kB"
     }
   ]
 }