Update to SystemC 3.0.1

Fix some of the deprecation warnings introduced in the new version such
as the removal of SC_HAS_PROCESS.

CMakeLists.txt

@@ -116,13 +116,10 @@ if (DRAMSYS_USE_FETCH_CONTENT)
 
         FetchContent_Declare(
             SystemCLanguage
-            URL https://github.com/accellera-official/systemc/archive/refs/tags/2.3.4.tar.gz
+            URL https://github.com/accellera-official/systemc/archive/refs/tags/3.0.1.tar.gz
             OVERRIDE_FIND_PACKAGE
         )
 
-        # TODO: remove with SystemC 3.0
-        set(CMAKE_CXX_STANDARD ${CMAKE_CXX_STANDARD} CACHE STRING "")
-
         FetchContent_MakeAvailable(SystemCLanguage)
 
         # Set include directories to SYSTEM to suppress warnings