feat(*): remove the network ns in the shim start

[Mossaka]

this commit removes the unnecessary nerwork namepsace setup in the shim start function because it is already been set in youki.

See #476

[jsturtevant]

The previous run failed, Did something change?

[Mossaka]

The previous run failed, Did something change?

Not really. Let me run the tests again

[Mossaka]

1 / 5 runs the CI failed

[Mossaka]

timeout error: https://github.com/containerd/runwasi/actions/runs/11864777519/job/33069084169?pr=503#step:7:1001

[jprendes]

That timeout error is linked to installing a debian package, so it can be ignored.

[jprendes]

@Mossaka , do you ha e a feel from all the runs you did if there are still failures linked to this? If so, what kind of failures? I'm inclined to think that any failures are just the sporadic timeouts we've seen in other places in CI as well.

[jprendes]

LGTM.
I'm happy with merging this. We csn revert if we notice any issues afterwards.

[Mossaka]

@Mossaka , do you ha e a feel from all the runs you did if there are still failures linked to this? If so, what kind of failures? I'm inclined to think that any failures are just the sporadic timeouts we've seen in other places in CI as well.

I believe all the failures are related to the sporadic timeouts