Remove unecessary preprocessor defines

This is already handled by disabling warning C4996

https://docs.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-3-c4996?view=msvc-170

CMakeLists.txt

@@ -196,8 +196,6 @@ endif()
 if(SFML_COMPILER_MSVC)
     # add an option to choose whether PDB debug symbols should be generated (defaults to true when possible)
     sfml_set_option(SFML_GENERATE_PDB TRUE BOOL "True to generate PDB debug symbols, FALSE otherwise.")
-
-    add_definitions(-D_CRT_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS)
 endif()
 
 # define SFML_OPENGL_ES if needed