Google API change breaks Vertex

[pinetops]

We're now getting this when making API requests in vertex API:
API keys are not supported by this API. Expected OAuth2 access token or other authentication credentials that assert a principal. See https://cloud.google.com/docs/authentication

The fix is to remove the api key from the url (leaving the bearer header).

[brainlid]

Well darn. Stupidly, the two Google LLMs have different APIs. The hope was we could add both versions and let the API use the one it cared about.

I'm not a regular user of the Google services. Do you have a suggestion or PR we could use?