CI: remove Node.js 22

The (outdated) nyc dependency supports Node.js 10 to 20

Author: lovell

.github/workflows/unit.yml

@@ -15,7 +15,6 @@ jobs:
           - 16
           - 18
           - 20
-          - 22
     steps:
       - name: Checkout
         uses: actions/checkout@v4