@actions/io: convert to ESM module

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@actions/io",
-  "version": "2.0.0",
+  "version": "3.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@actions/io",
-      "version": "2.0.0",
+      "version": "3.0.0",
       "license": "MIT"
     }
   }