fix: restore nodejs 16 compatibility

Fixes #1710

Author: robertsLando

package.json

@@ -92,7 +92,7 @@
     "lint"
   ],
   "engines": {
-    "node": ">=18.0.0"
+    "node": ">=16.0.0"
   },
   "browser": {
     "./mqtt.js": "./build/mqtt.js",