"String has no .name field or method" when using unsupported CL client

[Tomás Grüner]

Running kurtosis run github.com/kurtosis-tech/ethereum-package --args-file network_params.yaml with networks_params.yaml being:

participants:
  - el_type: geth
    cl_type: foo
    cl_image: bar
    vc_type: lighthouse
    validator_count: null
    count: 2

Results in the error:

Evaluation error: string has no .name field or method
        at [github.com/kurtosis-tech/ethereum-package/main.star:104:55]: run
        at [github.com/kurtosis-tech/ethereum-package/src/participant_network.star:166:34]: launch_participant_network
        at [github.com/kurtosis-tech/ethereum-package/src/cl/cl_launcher.star:117:42]: launch