chore(deps): update dependency rollup to v3.21.0

Author: renovate[bot]

ember-resources/package.json

@@ -160,7 +160,7 @@
     "expect-type": "^0.15.0",
     "prettier": "^2.8.4",
     "prettier-plugin-ember-template-tag": "^0.3.2",
-    "rollup": "3.20.7",
+    "rollup": "3.21.0",
     "rollup-plugin-copy": "^3.4.0",
     "rollup-plugin-ts": "^3.2.0",
     "tslib": "^2.5.0",