👷‍♀️ Update Node.js build matrix

Drop Node.js v16 support, and add v22 support in-line with the Node.js
[release schedule][1].

[1]: https://github.com/nodejs/release#release-schedule

Author: alecgibson

.github/workflows/test.yml

@@ -20,9 +20,9 @@ jobs:
       fail-fast: false
       matrix:
         node:
-        - 16
         - 18
         - 20
+        - 22
         mongodb:
         - 4.4
         - 5.0