refactor(provider): remove google-vertex-anthropic special case in ge…

[MichaelYochpaz]

Remove redundant google-vertex-anthropic special case in getSDK()

Context

The getSDK() function had a workaround that manually mapped google-vertex-anthropic to @ai-sdk/google-vertex/anthropic because models.dev was returning the incorrect NPM package (@ai-sdk/google-vertex).

This special case will no longer be needed once fix will be merged on anomalyco/models.dev#717

Related to #9894

Caution

Merge only after anomalyco/models.dev#717 is merged and the fix is applied on models.dev.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Based on my search, I found one potentially related PR:

PR #9568: "fix(provider): Resolve unversioned google-vertex-anthropic model IDs to versioned ones"

• fix(provider): Resolve unversioned google-vertex-anthropic model IDs to versioned ones #9568
• This PR is related as it also handles google-vertex-anthropic model ID resolution, which appears to be part of the broader issue being addressed in PR refactor(provider): remove google-vertex-anthropic special case in ge… #10743

This is not a strict duplicate, but rather a related PR addressing google-vertex-anthropic handling. PR #10743 is removing a special case workaround once the upstream fix on models.dev is merged, while PR #9568 handles versioned model ID resolution.