Use ON and OFF for CMake booleans

cmake/CompilerWarnings.cmake

@@ -4,7 +4,7 @@
 
 # Helper function to enable compiler warnings for a specific target
 function(set_target_warnings target)
-    option(CSFML_WARNINGS_AS_ERRORS "Treat compiler warnings as errors" FALSE)
+    option(CSFML_WARNINGS_AS_ERRORS "Treat compiler warnings as errors" OFF)
 
     set(MSVC_WARNINGS
         /W4 # Baseline reasonable warnings
@@ -55,7 +55,7 @@ function(set_target_warnings target)
 
     # Disable warnings as errors when using Clang on Windows to work around deprecation warnings in Windows APIs
     if(SFML_OS_WINDOWS AND (SFML_COMPILER_CLANG OR SFML_COMPILER_CLANG_CL))
-        set(CSFML_WARNINGS_AS_ERRORS FALSE)
+        set(CSFML_WARNINGS_AS_ERRORS OFF)
     endif()
 
     if(CSFML_WARNINGS_AS_ERRORS)