chore: remove support for node 12 (#870)

Author: ericapisani

package.json

@@ -54,7 +54,7 @@
     "upper-case-first": "^2.0.2"
   },
   "engines": {
-    "node": "^12.20.0 || ^14.14.0 || >=16.0.0"
+    "node": "^14.14.0 || >=16.0.0"
   },
   "ava": {
     "timeout": "2m",