Fix TimeoutConfigMergingTest to match runtime behavior

Author: vcjana

aws/codegen-aws-sdk/src/test/kotlin/software/amazon/smithy/rustsdk/TimeoutConfigMergingTest.kt

@@ -159,8 +159,6 @@ class TimeoutConfigMergingTest {
                             &TimeoutConfig::builder()
                                 .read_timeout(Duration::from_secs(10))
                                 .connect_timeout(connect_timeout)
-                                .disable_operation_attempt_timeout()
-                                .disable_operation_timeout()
                                 .build(),
                             "read timeout overridden"
                         );