CLI fails to retrieve bearer token

[wmiller112]

Checklist

• I've searched the issue queue to verify this is not a duplicate bug report.
• I've included steps to reproduce the bug.
• I've pasted the output of kargo version.
• I've pasted logs, if applicable.

Description

kargo login <url> --kubeconfig results in the following error:

Error: error retrieving bearer token from kubeconfig: %!w(<nil>)

Cluster is in EKS, so uses credentials plugin, but this appears to be supported. I get the same error if I generate a bearer token and set the user.token.

Steps to Reproduce

kargo login <url> --kubeconfig

Version

Client Version: v0.8.8
Server Version: v0.8.8