Update dependency @ember/string to v4

Author: renovate[bot]

package.json

@@ -55,7 +55,7 @@
   "devDependencies": {
     "@babel/plugin-proposal-decorators": "7.28.0",
     "@ember/optional-features": "2.2.0",
-    "@ember/string": "3.1.1",
+    "@ember/string": "4.0.1",
     "@ember/test-helpers": "3.3.1",
     "@embroider/test-setup": "3.0.3",
     "auto-dist-tag": "2.1.1",