fix(@ai-sdk/provider-utils): Use safeParseAsync for zod schemas (#7389)

## Background

To support `async` `refine` calls

## Summary

Changed calls of `safeParse` to `safeParseAsync`. Calls to `validate`
were already `await`ed.

## Verification

`pnpm link`ed into another project where I added a tool with an `async`
`refine` in its `inputSchema`. Without this change, it throws an error.

## Related Issues

Fixes #6868

Author: cwgorman

.changeset/sour-mails-clap.md

@@ -0,0 +1,5 @@
+---
+'@ai-sdk/provider-utils': patch
+---
+
+Adds support for async zod validators

packages/provider-utils/src/schema.ts

@@ -1,4 +1,4 @@
-import { Validator, validatorSymbol } from './validator';
+import { Validator, validatorSymbol, type ValidationResult } from './validator';
 import { JSONSchema7 } from '@ai-sdk/provider';
 import * as z3 from 'zod/v3';
 import * as z4 from 'zod/v4';
@@ -49,7 +49,7 @@ export function jsonSchema<OBJECT = unknown>(
   }: {
     validate?: (
       value: unknown,
-    ) => { success: true; value: OBJECT } | { success: false; error: Error };
+    ) => ValidationResult<OBJECT> | PromiseLike<ValidationResult<OBJECT>>;
   } = {},
 ): Schema<OBJECT> {
   return {

packages/provider-utils/src/zod-schema.ts

@@ -25,8 +25,8 @@ export function zod3Schema<OBJECT>(
       target: 'jsonSchema7', // note: openai mode breaks various gemini conversions
     }) as JSONSchema7,
     {
-      validate: value => {
-        const result = zodSchema.safeParse(value);
+      validate: async value => {
+        const result = await zodSchema.safeParseAsync(value);
         return result.success
           ? { success: true, value: result.data }
           : { success: false, error: result.error };
@@ -57,8 +57,8 @@ export function zod4Schema<OBJECT>(
   }) as JSONSchema7;
 
   return jsonSchema(z4JSONSchema, {
-    validate: value => {
-      const result = z4.safeParse(zodSchema, value);
+    validate: async value => {
+      const result = await z4.safeParseAsync(zodSchema, value);
       return result.success
         ? { success: true, value: result.data }
         : { success: false, error: result.error };