Set package.json minimum to Node 12.20 (microsoft#53183)

Author: jakebailey

package-lock.json

@@ -26,7 +26,7 @@
         "tsserver": "./bin/tsserver"
     },
     "engines": {
-        "node": ">=4.2.0"
+        "node": ">=12.20"
     },
     "files": [
         "bin",