relicense Vulkan backend as MIT

kompute/src/OpMemoryBarrier.cpp

@@ -1,13 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
 
-/**
- * Copyright (c) 2023 Nomic, Inc. All rights reserved.
- *
- * This software is licensed under the terms of the Software for Open Models License (SOM),
- * version 1.0, as detailed in the LICENSE_SOM.txt file. A copy of this license should accompany
- * this software. Except as expressly granted in the SOM license, all rights are reserved by Nomic, Inc.
- */
-
 #include "kompute/operations/OpMemoryBarrier.hpp"
 
 namespace kp {