Drop Node 12 support

Node 12 reached end-of-life on 2022-04-30.

Author: wimpyprogrammer

.github/workflows/tests.yml

@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [12.x]
+        node-version: [14.x]
         require-successful-testpack: [true]
         include:
           - node-version: 16.x

packages/strings-to-regex/package.json

@@ -18,7 +18,7 @@
   ],
   "sideEffects": false,
   "engines": {
-    "node": ">=12"
+    "node": ">=14"
   },
   "scripts": {
     "build": "tsc -b --clean && tsc -b",