qa: use shouldBeCalledTimes(1) versus shouldBeCalledOnce()

The latter is only available starting in 1.8.0, while the former is
available in all versions.

Author: weierophinney

test/CommonDispatcherTests.php

@@ -40,7 +40,7 @@ public function testDispatchNotifiesAllRelevantListenersAndReturnsEventWhenNoErr
         $this->getListenerProvider()
             ->getListenersForEvent($event)
             ->willReturn($listeners)
-            ->shouldBeCalledOnce();
+            ->shouldBeCalledTimes(1);
 
         $dispatcher = $this->getDispatcher();
 
@@ -91,7 +91,7 @@ public function isPropagationStopped() : bool
         $this->getListenerProvider()
             ->getListenersForEvent($event)
             ->willReturn($listeners)
-            ->shouldBeCalledOnce();
+            ->shouldBeCalledTimes(1);
 
         $dispatcher = $this->getDispatcher();
 

test/ErrorEmittingDispatcherTest.php

@@ -58,12 +58,12 @@ public function testDispatchesErrorEventIfAListenerRaisesAnExceptionAndThenReThr
         $this->provider
             ->getListenersForEvent($event)
             ->willReturn([$errorRaisingListener])
-            ->shouldBeCalledOnce();
+            ->shouldBeCalledTimes(1);
 
         $this->provider
             ->getListenersForEvent(Argument::type(ErrorEvent::class))
             ->willReturn([$errorListener])
-            ->shouldBeCalledOnce();
+            ->shouldBeCalledTimes(1);
 
         $this->expectException(RuntimeException::class);
         $this->expectExceptionMessage('TRIGGERED');