chore: Make shadps4 REUSE compliant

src/common/io_file.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
 #pragma once
 #include <cstdint>
 #include <filesystem>
@@ -39,4 +42,4 @@ public:
 
     // Sets the size of the file to "size" and returns whether it succeeded or not
     bool setSize(std::uint64_t size);
-};
+};