Bump minimum required node version to 18

Author: jeffesquivels

.github/workflows/build+test.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        node: [16, 18, 20]
+        node: [18, 20, 22]
     name: Test on node v${{ matrix.node }}
     steps:
     - uses: actions/checkout@v3

package.json

@@ -28,7 +28,7 @@
     "url": "https://github.com/nimiq/core-js.git"
   },
   "engines": {
-    "node": ">=16.20.2"
+    "node": ">=18.20.3"
   },
   "files": [
     "dist/node.js",