chore: update node engine requirement to >=20 (#46)

Author: shazron

package.json

@@ -49,7 +49,7 @@
     "typescript": "^4.5.2"
   },
   "engines": {
-    "node": ">=18"
+    "node": ">=20"
   },
   "jest": {
     "collectCoverage": true,