docs: fix no overload matches this call. (#4801)

Author: Josef-Friedrich

docs/config/index.md

@@ -1940,7 +1940,7 @@ import { defineConfig } from 'vitest/config'
 
 export default defineConfig({
   test: {
-    onConsoleLog(log: string, type: 'stdout' | 'stderr'): boolean | void {
+    onConsoleLog(log: string, type: 'stdout' | 'stderr'): false | void {
       if (log === 'message from third party library' && type === 'stdout')
         return false
     },