CMake: Rename serenity_* helper functions/macros to ladybird_*

Author: https://github.com/ayeteadoe
Commit: 25f5936dee
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5249
Reviewed-by: https://github.com/gmta ✅

Libraries/LibFileSystem/CMakeLists.txt

@@ -3,5 +3,5 @@ if (NOT WIN32)
    list(APPEND SOURCES TempFile.cpp)
 endif()
 
-serenity_lib(LibFileSystem filesystem)
+ladybird_lib(LibFileSystem filesystem)
 target_link_libraries(LibFileSystem PRIVATE LibCoreMinimal)