Migrate Antora makefile targets into top-level Makefile #952

Job	Run time
Run Vulkan CTS framework tests to validate against XML changes	1m 43s
Build the vulkan specification and generate any associated files (such as vulkan.h)	6m 5s
Build the core-only spec, to try and catch ifdef errors in extension markup	53s
Verify repository license compliance	40s
Build a test spec and check against expectation, to make sure the spec toolchain works as expected	1m 20s
Run various checker scripts on the spec and XML sources	50s
Generate Rust bindings (Ash crate)	44s
Generate the vulkan C++ header (vulkan.hpp)	1m 8s
Compile a simple test program that uses vulkan.h	13s
Build-test Rust bindings (Ash crate)	28s
Compile a simple test program that uses vulkan.hpp	22s
	14m 26s

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