[release/v1.33.x] Fix flaky http client test (#10914)

Co-authored-by: Lauri Tulmin <ltulmin@splunk.com>

Author: opentelemetrybot

testing-common/src/main/java/io/opentelemetry/instrumentation/testing/junit/http/AbstractHttpClientTest.java

@@ -7,6 +7,7 @@
 
 import static io.opentelemetry.api.common.AttributeKey.stringKey;
 import static io.opentelemetry.instrumentation.testing.util.TelemetryDataUtil.comparingRootSpanAttribute;
+import static io.opentelemetry.instrumentation.testing.util.TelemetryDataUtil.orderByRootSpanName;
 import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
 import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.equalTo;
 import static io.opentelemetry.semconv.SemanticAttributes.NetTransportValues.IP_TCP;
@@ -185,7 +186,8 @@ void shouldSuppressNestedClientSpanIfAlreadyUnderParentClientSpan(String method)
 
     assertThat(responseCode).isEqualTo(200);
 
-    testing.waitAndAssertTraces(
+    testing.waitAndAssertSortedTraces(
+        orderByRootSpanName("parent-client-span", "test-http-server"),
         trace ->
             trace.hasSpansSatisfyingExactly(
                 span -> span.hasName("parent-client-span").hasKind(SpanKind.CLIENT).hasNoParent()),