[v0.13] allow network.host daemon entitlement by default in container drivers

[tonistiigi]

Description

Based on comments in moby/buildkit#4524 (comment) , there shouldn't be a need to set --allowed-entitlemtns network.host as buildkitd flags when builder runs in a container as the container network is already isolated. At least when --driver-opt network does not equal host.

[crazy-max]

I think it would also makes sense for kubernetes driver (cc @AkihiroSuda)

[crazy-max]

I was wondering one thing. Should we set this entitlement silently when creating the builder or set it in buildx store? I think silently makes sense.