fix: cli: don't store auth provider info

[g-linville]

There was no need for us to be storing info about auth providers here. Each time the user authenticates with a new Obot instance, they will go through the auth flow, and the token will be saved locally. We won't need to know which auth provider it used again.

[sangee2004]

When testing with 0.5.1 release , following error is seen when switch ing between otto servers configured with different auth providers

2025/01/28 12:39:17 failed to fetch token: failed to create login request: invalid character 'a' looking for beginning of value

Able to switch between otto servers configured with different auth providers as expected with Version: v0.0.0-dev-35929b57-dirty version.

sangeethahariharan@Sangeethas-MBP bin % ./obot agents

Authentication is needed
========================

GitHub is used for authentication using the browser. This can be bypassed by setting
the env var OBOT_API_KEY to your API key.

Press ENTER to continue (CTRL+C to exit)


Opening browser to http://localhost:8080/api/oauth/start/bc0b9846-a173-4016-bcc8-3607a44599ef/default/github-auth-provider. if there is an issue paste this link into a browser manually
ID        NAME      DESCRIPTION         INVOKE                                     CREATED
a1-obot   Obot      Default Assistant   http://localhost:8080/api/invoke/obot      16 minutes ago
a1jp576   my test                       http://localhost:8080/api/invoke/a1jp576   12 minutes ago
sangeethahariharan@Sangeethas-MBP bin % export OBOT_BASE_URL=https://main.acornlabs.com/api
sangeethahariharan@Sangeethas-MBP bin % ./obot agents                                      
Opening browser to https://main.acornlabs.com/api/oauth/start/3dc88c3e-deb1-40bc-87e1-ed3f374f9819/default/google-auth-provider. if there is an issue paste this link into a browser manually
ID        NAME                          DESCRIPTION         INVOKE                                              CREATED
a1-obot   Obot                          Default Assistant   https://main.acornlabs.com/api/invoke/obot          1 week ago