dpl: fix copyright year

Signed-off-by: Augusto Berndt <augusto.berndt@precisioninno.com>

Author: gudeh

src/dpl/src/NegotiationLegalizer.cpp

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: BSD-3-Clause
-// Copyright (c) 2018-2025, The OpenROAD Authors
+// Copyright (c) 2018-2026, The OpenROAD Authors
 
 #include "NegotiationLegalizer.h"
 

src/dpl/src/NegotiationLegalizer.h

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: BSD-3-Clause
-// Copyright (c) 2018-2025, The OpenROAD Authors
+// Copyright (c) 2018-2026, The OpenROAD Authors
 
 #pragma once
 

src/dpl/src/NegotiationLegalizerPass.cpp

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: BSD-3-Clause
-// Copyright (c) 2018-2025, The OpenROAD Authors
+// Copyright (c) 2018-2026, The OpenROAD Authors
 
 #include <algorithm>
 #include <cmath>