shell: drop --wait
This flag is deprecated in Kubernetes 1.26 and removed in 1.29; according to Kubernetes commit 09804a198c 1 it has no effect, at least as of Kubernetes 1.26 (it’s not entirely clear whether it ever had an effect or not).
Very recently, Kubernetes 1.31 apparently added a --wait flag to
kubectl run
again 2, but I very much doubt that Bryan foresaw this
and intended to refer to that flag when he added --wait=true in change
I8be6562acd (commit fd2d21a3) four years ago.
Bug: T373866
Resubmit of !54 (closed) from a branch in the same repo, so CI can work properly.