Pin dependencies

Author: renovate[bot]

package.json

@@ -41,7 +41,7 @@
     "@babel/eslint-parser": "7.28.4",
     "@babel/plugin-proposal-decorators": "7.28.0",
     "@ember/optional-features": "2.2.0",
-    "@ember/string": "^4.0.1",
+    "@ember/string": "4.0.1",
     "@ember/test-helpers": "5.3.0",
     "@embroider/test-setup": "4.0.0",
     "@glimmer/component": "1.1.2",
@@ -54,7 +54,7 @@
     "ember-changeset": "5.0.0",
     "ember-changeset-validations": "5.0.0",
     "ember-cli": "6.7.0",
-    "ember-cli-clean-css": "^3.0.0",
+    "ember-cli-clean-css": "3.0.0",
     "ember-cli-dependency-checker": "3.3.3",
     "ember-cli-inject-live-reload": "2.1.0",
     "ember-cli-sri": "2.1.1",