[INTERNAL] CI: Test on Node 16

Author: matz3

.github/workflows/github-ci.yml

@@ -35,7 +35,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [15]
+        node-version: [16]
         os: [ubuntu-latest, windows-latest, macOS-latest]
         include:
           - node-version: 10