fix(tests): fix file test

Author: dtmeadows

openai-java-core/src/test/kotlin/com/openai/models/containers/files/FileCreateParamsTest.kt

@@ -72,9 +72,7 @@ internal class FileCreateParamsTest {
  InputStream::class.java,
  )
  .isEqualTo(
- mapOf().mapValues { (_, field) ->
- field.map { (it as? ByteArray)?.inputStream() ?: it }
- }
+ mapOf<String, MultipartField<*>>()
  )
  }
 }