Backport: fix(google-vertex): don't send streamFunctionCallArguments for vertex doGenerate

[vercel-ai-sdk]

This is an automated backport of #14352 to the release-v6.0 branch. FYI @aayush-kapoor
This backport has conflicts that need to be resolved manually.

git cherry-pick output

Auto-merging packages/google/src/google-generative-ai-language-model.test.ts
Auto-merging packages/google/src/google-generative-ai-language-model.ts
CONFLICT (content): Merge conflict in packages/google/src/google-generative-ai-language-model.ts
error: could not apply 5b7e7c2a9... fix(google-vertex): don't send streamFunctionCallArguments for vertex doGenerate (#14352)
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"

[vercel-ai-sdk]

🚀 Published in:

Package	Version
@ai-sdk/google	3.0.62
@ai-sdk/google-vertex	4.0.108