Merge pull request #582 from ember-a11y/dependabot/npm_and_yarn/ember/string-4.0.1

Bump @ember/string from 3.1.1 to 4.0.1

Author: MelSumner

package.json

@@ -77,7 +77,7 @@
   },
   "devDependencies": {
     "@ember/optional-features": "^2.0.0",
-    "@ember/string": "^3.1.1",
+    "@ember/string": "^4.0.1",
     "@ember/test-helpers": "^3.0.3",
     "@embroider/test-setup": "^4.0.0",
     "@glimmer/component": "^1.0.4",