google.golang.org/api/generativelanguage/v1beta is not yet properly published

### Description of the bug:

https://pkg.go.dev/google.golang.org/api
doesn't contain "generativelanguage" sub package.

But it's listed there as the canonical path:
https://github.com/google/generative-ai-go/blob/main/genai/internal/generativelanguage/v1beta/generativelanguage-gen.go#L61

### Actual vs expected behavior:

Protobuf source of truth is at google.golang.org/api/generativelanguage/v1beta.

### Any other information you'd like to share?

_No response_