[FEATURE] Ability to pass in `--platform` for docker client while creating clusters/nodes

[cenk1cenk2]

Is your feature request related to a problem or a Pull Request

Please link to the issue/PR here and explain how your request is related to it.

• In need to run k3d as amd on mac m1 #1031 -> This has been raised here as a discussion but workarounds are proposed.

Scope of your request

• a new flag for a command
  • proposing a --platform argument here for commands cluster create and node create
• config entry
  • proposing a config entry as follows

    options:
      platforms:
         - platform: linux/arm64/v8
           nodeFilters:
               - server:*
               - agent:*

Describe the solution you'd like

Currently k3d can not create an emulated environment in linux/amd64 environment for linux/arm64/v8 or similar since in https://github.com/k3d-io/k3d/blob/main/pkg/runtimes/docker/container.go#L54-L54, containers are created without the ocispecv1.Platform as nil. The docker go client does not directly support DOCKER_DEFAULT_PLATFORM environment variable to set this automatically like the CLI.

• I would propose to implement a flag called --platform where this gets passed into cluster create and node create commands, where the user can set a platform for the created cluster or node.
• This can be also added to the config file under options.runtime.platform. This should be also relevant to the master and worker nodes as well as loadbalancer and tool containers. However a nodeFilters mechanism can be implemented here, like the labels to make this more configurable.

Describe alternatives you've considered

• Pulling and running the images with the designated architecture like rancher/k3s:v1.32.7-k3s1-arm64 does not work properly.

Notes

I can implement this as a contribution; however, I am not sure if this would be an appropriate merge request for the repository and would be accepted. Therefore, I am opening up an issue first to get your input on it.