Add a no-cache option to the command line to allow one-off full rebuilds

[alexkreidler]

#2054 enabled support for the Docker --no-cache CLI flag in the skaffold.yaml file under each artifact.

However, my use case is that I want to select a subset of artifacts using skaffold build -b="artifact-1" and build them from scratch without a Docker (or BuildKit in my case) cache.

It would be great to have this as a CLI flag. I initially thought --cache-artifacts=false might do the trick, but it didn't.

It seems like maybe there should even be a meta-flag like --cache=false that could disable all forms of caching, from the build provider (docker or others) to Skaffold itself (with the cache-artifacts flag). Just something else to think about. If others express interest in that option, I can open another issue. I'm really enjoying skaffold so far!

[briandealwis]

A broad --cache=true/false is an interesting idea!

[dhodun]

+1 - this would be helpful when debugging CloudBuild concurrency issues.

Currently we have to make dummy edits to files across multiple service to trigger rebuilds.

[TatyanaKavalenkaTR]

+1

[jay-docusign]

+1