ci: remove node 16 from test matrix

Author: pi0

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [16, 18, 20]
+        node: [18, 20]
     steps:
       - uses: actions/checkout@v4
         with: