Also drop official Node 16 support

Because of a breaking lockfile version change between Node 16 and 18, it's not possible to test Node 16, 18 and 20 in one CI pipeline.

Author: jhnns

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [16.x, 18.x, 20.x]
+        node-version: [18.x, 20.x]
 
     steps:
       - name: 🛑 Cancel Previous Runs