chore!: remove Node.js 21.x from the range of supported versions

Node.js EOL was Jun 6, 2024 and is unsupported

Author: MikeMcC399

.github/workflows/ci.yml

@@ -48,7 +48,6 @@ jobs:
         node:
           - 18
           - 20
-          - 21
           - 22
         platform:
           - ubuntu-latest

package.json

@@ -10,7 +10,7 @@
     "url": "https://github.com/nodejs/corepack.git"
   },
   "engines": {
-    "node": "^18.17.1 || >=20.10.0"
+    "node": "^18.17.1 || ^20.10.0 || >=22.0.0"
   },
   "exports": {
     "./package.json": "./package.json"