fix(tsconfig): test config uses NodeNext — Node16 was flagged deprecated by user's TS service

User's IDE flagged 'Node16' as deprecated even though TS 5.9.3
accepts it without warning at compile time. NodeNext is the current
non-deprecated value and pairs cleanly with our CommonJS-emitting
test compile (NodeNext auto-detects module format from package.json
type field — our extension package.json has no 'type' so commonjs).

Author: George-iam

extension/test/tsconfig.json

@@ -1,8 +1,8 @@
 {
   "compilerOptions": {
     "target": "ES2022",
-    "module": "Node16",
-    "moduleResolution": "Node16",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
     "lib": ["ES2022"],
     "strict": true,
     "esModuleInterop": true,