chore: Replace node 21 with 22 for server-node CI. (#838)

The rennovate PR adjusts all the builds which just use node as a tool,
but server-node is using a range of versions for validation. This
updates the versions to be 18 and 22 instead of 18 and 21.

Author: kinyoklion

.github/workflows/server-node.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         # Node versions to run on.
-        version: [18, 21]
+        version: [18, 22]
 
     steps:
       - uses: actions/checkout@v4