Remove manual fence synchronization #801

Job	Run time
Rocky Linux	2m 14s
Debian Linux PPC SDL3	58s
Debian Linux PPC	1m 50s
Rocky Linux MinGW	57s
FreeBSD	1m 14s
macOS (x86_64)	31s
Windows (MSVC)	1m 27s
Rocky Linux SDL3	1m 17s
iOS/tvOS SDL3 (iOS, iphoneos, arm64)	53s
iOS/tvOS SDL3 (iOS, iphonesimulator, x86_64;arm64)	1m 2s
macOS (Universal) SDL3	1m 13s
Rocky Linux MinGW SDL3	1m 1s
iOS/tvOS SDL3 (tvOS, appletvos, arm64)	42s
iOS/tvOS SDL3 (tvOS, appletvsimulator, x86_64;arm64)	1m 7s
	16m 26s

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