engine: common: remove unused D_ enum used for MsgDev in old engine. … #2711

Job	Run time
flatpak (su.xash.Engine.Compat.i386)	6m 4s
build (ubuntu-20.04, linux, amd64)	3m 47s
build (ubuntu-20.04, linux, i386)	3m 47s
build (ubuntu-20.04, linux, arm64, true)	4m 0s
build (ubuntu-20.04, linux, armhf, true)	3m 34s
build (ubuntu-20.04, linux, riscv64, true)	3m 19s
build (ubuntu-20.04, linux, ppc64el, true)	3m 37s
build (ubuntu-20.04, android, multiarch)	11m 0s
build (ubuntu-latest, nswitch, arm64)	3m 17s
build (ubuntu-latest, psvita, armv7hf)	8m 16s
build (windows-latest, win32, amd64)	2m 44s
build (windows-2019, win32, i386)	2m 34s
build (macos-14, apple, arm64)	1m 53s
build (macos-13, apple, amd64)	2m 57s
Upload releases	49s
	1h 1m 38s

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