Docker Hub TLS handshakes are too flaky to make pre-pulling a hard bootstrap
requirement. Treat image pre-pull as opportunistic and disable Rancher's
managed system-upgrade-controller feature so that image is removed from the
critical install path while Rancher and its webhook converge.
Rancher installs were stalling on transient Docker Hub TLS handshake timeouts
for rancher shell, webhook, and system-upgrade-controller images. Pre-pull the
required images onto all nodes after k3s comes up, extend the Rancher HelmRelease
timeout, and reset/force the Rancher HelmRelease before waiting on addon-rancher
so bootstrap can recover from stale failed remediation state.
micqdf