feat: add kubectl-oidc_login plugin

[jbeard6]

Summary

Adds the kubectl-oidc_login plugin to the repository.

Note: the tool being installed calls itself kubelogin but, due to the name being overloaded (e.g. another plugin in this repo), it is installed as kubectl-oidc_login (reference). This is why this name was chosen for the plugin.

Description:

• Tool repo URL: int128/kubelogin
• Plugin repo URL: ezcater/asdf-kubectl-oidc_login

Note: this is a recreation of #1067 which was closed because we accidentally cleaned up our fork of this repo.

Checklist

• Format with scripts/format.bash
• Test locally with scripts/test_plugin.bash --file plugins/<your_new_plugin_name>
• Your plugin CI tests are green
  • Tip: use the plugin_test action from asdf-actions in your plugin CI