The function currently has 2 purposes: (1) To copy dependent dlls for
executables to output binary directory. This ensures that these helper
processes can be ran after a build given not all DLLs from vcpkg libs
get implicitly copied to the bin folder. (2) Allow fully background
and/or GUI processes to use the Windows Subsystem. This prevents
unnecessarily launching a console for the process, as we either require
no user interaction or the user interaction is all handled in the GUI.
The BUILD_RPATH/INSTALL_RPATH CMake infrastructure is not supported
on Windows, but we want to ensure Ladybird executables are runnable
after the build phase so there can be an efficient dev loop.
lagom_copy_runtime_dlls() can be used by executable targets so all
their dependent dlls are copied to their output directory in their
post build step.
