test(bigquery): Fix flaky ITBigQueryTest#testOpenTelemetryTracingQuery (googleapis#12769)

b/467063732

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: jinseopkim0

java-bigquery/google-cloud-bigquery/src/test/java/com/google/cloud/bigquery/it/ITBigQueryTest.java

@@ -7889,7 +7889,17 @@ public void testOpenTelemetryTracingQuery() throws InterruptedException {
     bigquery.getOptions().setDefaultJobCreationMode(JobCreationMode.JOB_CREATION_OPTIONAL);
     TableResult tableResult = executeSimpleQuery(bigquery);
     assertNotNull(tableResult.getQueryId());
-    assertNull(tableResult.getJobId());
+
+    // Safely handle the fallback where BigQuery determines a job must be created
+    // even if the mode is optional. Most requests will be stateless, but it is still
+    // possible that the BQ engine will create a job even for tiny requests.
+    if (tableResult.getJobCreationReason() != null) {
+      assertNotNull(tableResult.getJobId());
+      assertEquals(tableResult.getQueryId(), tableResult.getJobId().getJob());
+      assertEquals(JobCreationReason.Code.OTHER, tableResult.getJobCreationReason().getCode());
+    } else {
+      assertNull(tableResult.getJobId());
+    }
 
     assertNotNull(OTEL_ATTRIBUTES.get("com.google.cloud.bigquery.BigQuery.queryRpc"));
     assertNotNull(