Queue::fake the two cancel/terminate-while-waiting-on-activity tests

Same bucket A pattern as d042ea9: tests that wait for the workflow
to park on an activity were racing the real testbench queue workers.
Activity-wait variants weren't covered by d042ea9 (which only handled
timer-wait variants).

Conversion uses runReadyTaskForRun(Workflow) before the waitFor instead
of drainReadyTasks because draining further would also run the dispatched
activity task and complete the activity before the test could cancel.
After the cancel, drainReadyTasks finishes the cancellation workflow task
chain.

Clears 2 CI-only MySQL failures under #399:
  * testWorkflowCanBeCancelledWithReasonWhileWaitingOnActivity
  * testWorkflowCanBeTerminatedWithReasonWhileWaitingOnActivity

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: durable-workflow-ops

tests/Feature/V2/V2WorkflowTest.php

@@ -7731,18 +7731,24 @@ public function testRepairReturnsAcceptedNoOpForRowOnlyOpenChildFallback(): void
 
     public function testWorkflowCanBeCancelledWithReasonWhileWaitingOnActivity(): void
     {
+        Queue::fake();
+
         $workflow = WorkflowStub::make(TestHeartbeatWorkflow::class, 'cancel-activity-wait');
         $workflow->start();
 
         $runId = $workflow->runId();
 
         $this->assertNotNull($runId);
 
+        $this->runReadyTaskForRun($runId, TaskType::Workflow);
+
         $this->waitFor(static fn (): bool => $workflow->refresh()->status() === 'waiting'
             && $workflow->summary()?->wait_kind === 'activity');
 
         $result = $workflow->cancel('Customer requested cancellation');
 
+        $this->drainReadyTasks();
+
         $this->assertTrue($result->accepted());
         $this->assertSame('cancel', $result->type());
         $this->assertSame('cancelled', $result->outcome());
@@ -7815,18 +7821,24 @@ public function testWorkflowCanBeCancelledWithReasonWhileWaitingOnActivity(): vo
 
     public function testWorkflowCanBeTerminatedWithReasonWhileWaitingOnActivity(): void
     {
+        Queue::fake();
+
         $workflow = WorkflowStub::make(TestHeartbeatWorkflow::class, 'terminate-activity-wait');
         $workflow->start();
 
         $runId = $workflow->runId();
 
         $this->assertNotNull($runId);
 
+        $this->runReadyTaskForRun($runId, TaskType::Workflow);
+
         $this->waitFor(static fn (): bool => $workflow->refresh()->status() === 'waiting'
             && $workflow->summary()?->wait_kind === 'activity');
 
         $result = $workflow->terminate('Operator emergency shutdown');
 
+        $this->drainReadyTasks();
+
         $this->assertTrue($result->accepted());
         $this->assertSame('terminate', $result->type());
         $this->assertSame('terminated', $result->outcome());