feat: introduce option to ignore incompatibility between available clients and server

[flavio]

It would be nice to have a flag (and hence an env variable) that forces the usage of the most recent version of the kubectl binary available on the system, even if it's incompatible with the remote server.

This could help in such a scenario

• airgap environment
• kuberlr is configured to not download kubectl binaries
• a bunch of kubectl binaries are already available on the system
• user needs to interact with a server, but there's no compatible binary already downloaded