fix(lambda-runtime): change fallback for latest lambda node runtime to node 22.x

packages/aws-cdk-lib/aws-lambda/lib/runtime.ts

@@ -420,7 +420,7 @@ export class Runtime {
 export function determineLatestNodeRuntime(scope: Construct): Runtime {
   // Runtime regional fact should always return a known runtime string that Runtime can index off, but for type
   // safety we also default it here.
-  const runtimeName = Stack.of(scope).regionalFact(FactName.LATEST_NODE_RUNTIME, Runtime.NODEJS_18_X.name);
+  const runtimeName = Stack.of(scope).regionalFact(FactName.LATEST_NODE_RUNTIME, Runtime.NODEJS_22_X.name);
   return new Runtime(runtimeName, RuntimeFamily.NODEJS, { supportsInlineCode: true, isVariable: true });
 }