chore: drop Node 20 support, require Node >=22

Node 20 reached end-of-life on April 30 2026. cspell v10 and other
updated devDependencies now require Node >=22.18.0, making Node 20
incompatible with the dev toolchain.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: DHoefakker

.circleci/config.yml

@@ -74,7 +74,6 @@ workflows:
           matrix:
             parameters:
               node-version:
-                - "20"
                 - "22"
       - Prettier
       - Lint

package.json

@@ -15,7 +15,7 @@
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "engines": {
-    "node": ">=16.0"
+    "node": ">=22"
   },
   "scripts": {
     "build": "tsc --build tsconfig.build.json",