fix(spec): LanguageModelV3ToolResult["result"] change from unknown to NonNullable<JSONValue> (#9931)

## Background

Discovered in
#9896 (review)

## Summary

As far as I can tell, `result` has to be set to something that is not
null or undefined. This makes the spec more precise and would have
surfaced the problem of
#9896 (review)
immediately

## Manual Verification

When the fix from this PR is applied, a type error is thrown in
#9896

Author: gr2m

.changeset/lemon-roses-yawn.md

@@ -0,0 +1,5 @@
+---
+'@ai-sdk/provider': patch
+---
+
+fix(spec): `LanguageModelV3ToolResult["result"]` change from `unknown` to `NonNullable<JSONValue>`

packages/openai/src/responses/openai-responses-api.ts

@@ -403,7 +403,10 @@ export const openaiResponsesChunkSchema = lazySchema(() =>
             results: z
               .array(
                 z.object({
-                  attributes: z.record(z.string(), z.unknown()),
+                  attributes: z.record(
+                    z.string(),
+                    z.union([z.string(), z.number(), z.boolean()]),
+                  ),
                   file_id: z.string(),
                   filename: z.string(),
                   score: z.number(),
@@ -624,7 +627,10 @@ export const openaiResponsesResponseSchema = lazySchema(() =>
             results: z
               .array(
                 z.object({
-                  attributes: z.record(z.string(), z.unknown()),
+                  attributes: z.record(
+                    z.string(),
+                    z.union([z.string(), z.number(), z.boolean()]),
+                  ),
                   file_id: z.string(),
                   filename: z.string(),
                   score: z.number(),

packages/provider/src/language-model/v3/language-model-v3-tool-result.ts

@@ -1,3 +1,4 @@
+import { JSONValue } from '../../json-value';
 import { SharedV3ProviderMetadata } from '../../shared/v3/shared-v3-provider-metadata';
 
 /**
@@ -19,7 +20,7 @@ export type LanguageModelV3ToolResult = {
   /**
    * Result of the tool call. This is a JSON-serializable object.
    */
-  result: NonNullable<unknown>;
+  result: NonNullable<JSONValue>;
 
   /**
    * Optional flag if the result is an error or an error message.