Use the / operator instead of join_paths
Use the / operator instead of using "/" in string paths
Use the includedir opt instead of hardcoding "include" in install_subdir
Remove discouraged layout=flat option (mesonbuild/meson#9243)
Remove unneeded Wextra, Wpedantic flags, already added by warning_level
Remove manual -Oz flag when using Clang (mesonbuild/meson#9286)
Make use of : in kwargs consistent
73870cef54