This commit replaces the git submodule for the Vulkan headers with meson subproject using wrap.
Signed-off-by: Stephan Lachnit <stephanlachnit@protonmail.com>
vk_dispatch_table_helper.h and vk_layer_dispatch_table.h headers
are not used anymore by mesa layer, remove their generation.
Remove git modules required only for the generation of above headers.