Fix Speakeasy targets in GitHub actions

[dumontg]

This PR fixes the CI for GCP and Azure SDKs:

• The GitHub actions now reference the correct Speakeasy targets
• Fixes issues in packages/mistralai_gcp/src/mistralai_private_gcp/sdk.py (not tracked by Speakeasy since we added gcloud authentication)
  • Dropped the use of SDKError for non-HTTP errors (it now expects a raw_response in its constructor and internally makes accesses to its attributes). They have been replaced with ValueError when relevant (aligned with elsewhere in the SDK for invalid inputs) or basic Exceptions.
  • Changed the return type GoogleCloudBeforeRequestHook#before_request to a union like in the base class.