Delete test that is no longer needed

tests/unit/Framework/MockObject/Creation/MockBuilderTest.php

@@ -72,21 +72,4 @@ public function testCreatesPartialMockObjectForExtendableClass(): void
 
         $this->assertTrue($double->doSomething());
     }
-
-    #[IgnorePhpunitDeprecations]
-    #[TestDox('allowMockingUnknownTypes() can be used to allow mocking of unknown types')]
-    public function testCreatesMockObjectForUnknownType(): void
-    {
-        $type = 'Type_' . substr(md5((string) mt_rand()), 0, 8);
-
-        assert(!class_exists($type) && !interface_exists($type) && !trait_exists($type));
-
-        $double = $this->getMockBuilder($type)
-            ->allowMockingUnknownTypes()
-            ->getMock();
-
-        $this->assertInstanceOf($type, $double);
-        $this->assertInstanceOf(MockObject::class, $double);
-
-    }
 }