ci: stop testing against NodeJS v14, v16 (#581)

BREAKING CHANGE: Drop support for NodeJS v14, v16

Author: wolfy1339

.github/workflows/test.yml

@@ -14,9 +14,8 @@ jobs:
     strategy:
       matrix:
         node_version:
-          - 14
-          - 16
           - 18
+          - 20
     steps:
       - uses: actions/checkout@v3
       - name: Use Node.js ${{ matrix.node_version }}

package.json

@@ -96,6 +96,6 @@
     ]
   },
   "engines": {
-    "node": ">= 14"
+    "node": ">= 18"
   }
 }