Fix BulkInferenceExecutorTests timeout failures by reducing test load and increasing min thread pool size

Author: afoucret

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/inference/bulk/BulkInferenceExecutorTests.java

@@ -47,7 +47,7 @@ public void setThreadPool() {
             new FixedExecutorBuilder(
                 Settings.EMPTY,
                 EsqlPlugin.ESQL_WORKER_THREAD_POOL_NAME,
-                between(1, 20),
+                between(4, 20),
                 1024,
                 "esql",
                 EsExecutors.TaskTrackingConfig.DEFAULT
@@ -61,7 +61,7 @@ public void shutdownThreadPool() {
     }
 
     public void testSuccessfulExecution() throws Exception {
-        List<InferenceAction.Request> requests = randomInferenceRequestList(between(1, 1000));
+        List<InferenceAction.Request> requests = randomInferenceRequestList(between(1, 100));
         List<InferenceAction.Response> responses = randomInferenceResponseList(requests.size());
 
         InferenceRunner inferenceRunner = mockInferenceRunner(invocation -> {
@@ -93,7 +93,7 @@ public void testSuccessfulExecutionOnEmptyRequest() throws Exception {
     }
 
     public void testInferenceRunnerAlwaysFails() throws Exception {
-        List<InferenceAction.Request> requests = randomInferenceRequestList(between(1, 1000));
+        List<InferenceAction.Request> requests = randomInferenceRequestList(between(1, 100));
 
         InferenceRunner inferenceRunner = mock(invocation -> {
             runWithRandomDelay(() -> {
@@ -115,7 +115,7 @@ public void testInferenceRunnerAlwaysFails() throws Exception {
     }
 
     public void testInferenceRunnerSometimesFails() throws Exception {
-        List<InferenceAction.Request> requests = randomInferenceRequestList(between(1, 1000));
+        List<InferenceAction.Request> requests = randomInferenceRequestList(between(1, 100));
 
         InferenceRunner inferenceRunner = mockInferenceRunner(invocation -> {
             ActionListener<InferenceAction.Response> listener = invocation.getArgument(1);