fix(quarkus-extesion/engine): Turn off JobExecutor

Problem Description:

- ManagedJobExecutorTest#shouldExecuteJob was failing sporadically on CI due to the asynchronous execution of scheduled jobs.
  The synchronous execution of the test would query for the existence of the job. Sometimes, the job would be already completed
  by the time the Query API would make assertions on its existence and that would lead into failures.

Solution:

- Turn off the job scheduler before filing any job executions

Related-to: #3940

quarkus-extension/engine/deployment/src/test/java/org/camunda/bpm/quarkus/engine/test/ManagedJobExecutorTest.java

@@ -16,13 +16,18 @@
  */
 package org.camunda.bpm.quarkus.engine.test;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.camunda.bpm.engine.impl.test.TestHelper.waitForJobExecutorToProcessAllJobs;
+
 import io.quarkus.test.QuarkusUnitTest;
+import jakarta.enterprise.context.ApplicationScoped;
+import jakarta.enterprise.inject.Produces;
+import jakarta.inject.Inject;
 import org.camunda.bpm.engine.ManagementService;
 import org.camunda.bpm.engine.ProcessEngine;
 import org.camunda.bpm.engine.RuntimeService;
 import org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl;
 import org.camunda.bpm.engine.impl.jobexecutor.JobExecutor;
-import org.camunda.bpm.engine.impl.test.TestHelper;
 import org.camunda.bpm.engine.runtime.ProcessInstance;
 import org.camunda.bpm.engine.test.Deployment;
 import org.camunda.bpm.quarkus.engine.extension.QuarkusProcessEngineConfiguration;
@@ -35,12 +40,6 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
-import jakarta.enterprise.context.ApplicationScoped;
-import jakarta.enterprise.inject.Produces;
-import jakarta.inject.Inject;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
 public class ManagedJobExecutorTest {
 
   @RegisterExtension
@@ -129,6 +128,7 @@ public void shouldNotReuseManagedExecutor() {
   @Deployment
   public void shouldExecuteJob() {
     // given
+    processEngineConfiguration.getJobExecutor().shutdown();
     ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("asyncTaskProcess");
 
     // when
@@ -137,14 +137,16 @@ public void shouldExecuteJob() {
         .processInstanceId(processInstance.getId())
         .count();
 
-    TestHelper.waitForJobExecutorToProcessAllJobs(processEngineConfiguration, 5000l, 25l);
-
     // then
     assertThat(jobCount).isOne();
+
+    waitForJobExecutorToProcessAllJobs(processEngineConfiguration, 5000L, 25L);
+
     jobCount = managementService
         .createJobQuery()
         .processInstanceId(processInstance.getId())
         .count();
+
     assertThat(jobCount).isZero();
   }