Remove Vulkan renderer (for real this time) #766

Job	Run time
Rocky Linux	1m 41s
iOS/tvOS SDL3 (iOS, iphoneos, arm64)	46s
FreeBSD	1m 17s
iOS/tvOS SDL3 (iOS, iphonesimulator, x86_64;arm64)	54s
Rocky Linux MinGW	58s
Rocky Linux MinGW SDL3	1m 7s
iOS/tvOS SDL3 (tvOS, appletvos, arm64)	42s
Debian Linux PPC	1m 41s
iOS/tvOS SDL3 (tvOS, appletvsimulator, x86_64;arm64)	1m 8s
Debian Linux PPC SDL3	59s
Rocky Linux SDL3	1m 29s
macOS (x86_64)	27s
macOS (Universal) SDL3	1m 4s
Windows (MSVC)	1m 31s
	15m 44s

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