[Tests] Replace setMethods() by onlyMethods() and addMethods()

Author: alexandre-daubois

Tests/Session/Storage/Handler/MemcachedSessionHandlerTest.php

@@ -45,7 +45,7 @@ protected function setUp(): void
 
         $this->memcached = $this->getMockBuilder(\Memcached::class)
             ->disableOriginalConstructor()
-            ->setMethods($methodsToMock)
+            ->onlyMethods($methodsToMock)
             ->getMock();
 
         $this->storage = new MemcachedSessionHandler(