The `flux events` command always applied a namespace filter, even when `--all-namespaces` was set.
This produced incomplete results and confused users expecting cluster-wide events.
Changes made:
* Build `clientListOpts` dynamically.
* Omit `client.InNamespace(...)` when `eventArgs.allNamespaces` is true, ensuring no namespace constraint.
Impact:
`flux events --all-namespaces` now returns events from every namespace, restoring expected functionality without affecting other options.
Signed-off-by: S. M. Mohiuddin Khan Shiam <147746955+mohiuddin-khan-shiam@users.noreply.github.com>