No longer need HostProcess specific build since containerd pr merged

[jsturtevant]

Reason for PR:

Removes the HostProcess build as containerd/containerd#5131 has merged.

Issue Fixed:

Issue #

Requirements

• Sqaush commits
• Documentation
• Tests

Notes:

[jsturtevant]

/cc @marosset

[marosset]

Can we just disable it for now?
I think we're going to want to be able to target dev branches for some work in the future.

[jsturtevant]

I lean toward removing it to avoid confusion several months later when we revisit if the requirement for dev branches is required. This was really to fill a gap while we landed it across all of the moving parts. The less custom stuff we have the better IMO.

[marosset]

Can we keep this around (but disabled) until the KEP to move HostProcess containers to beta gets reviewed (Sept 9 is the enhancement freeze)?
After the KEP review we'll have a much better idea what kinds of changes we'll be making for hcsshim and/or containerd and if those changes would justify keeping the forked builds around?

[marosset]

/lgtm

I spoke w/ @jsturtevant offline and we decided we'll just bring back the workflow if needed to keep the repo tidy.

[k8s-ci-robot]

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