Fix ParallelWaitError in forEachIsolateHelper during service disconnect (#10074)

`forEachIsolateHelper` used `[for (final isolate in vmIsolates) callback(isolate)].wait`.
In Dart 3, the `Iterable.wait` extension wraps any error from completed futures
in a `ParallelWaitError<V, E>`.

When a target application exits or a VM Service connection is shut down while an
operation is in flight (e.g. periodic polling in `refreshNetworkData`), VM Service
methods like `getSocketProfileWrapper` throw `RPCError: (112) Service has disappeared`.
Callers catch typed errors (e.g., `on RPCError catch (e)` in `network_service.dart` or
`on SentinelException` / `on RPCError` in `service_extension_manager.dart`) and check
`e.isServiceDisposedError` to safely swallow teardown exceptions.

Because `ParallelWaitError` does not inherit from `RPCError` or `Exception`, it bypassed
these typed catch blocks and escaped uncaught, causing flaky integration test failures
in `network_screen_test.dart`.

Using `Future.wait` preserves the underlying exception type thrown by the isolate
callback. Also update `_enableNetworkTrafficRecordingOnAllIsolates` to use `Future.wait`.