Bump version to 0.9.4 #196

Job	Run time
linux (x86_64-unknown-linux-gnu)	5m 20s
linux-cross (aarch64-unknown-linux-gnu, aarch64, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	6m 6s
linux-cross (armv7-unknown-linux-gnueabihf, armv7)	5m 42s
linux (i686-unknown-linux-gnu)	6m 34s
macos-aarch64	4m 52s
linux-cross (s390x-unknown-linux-gnu, s390x)	6m 31s
linux-cross (powerpc64le-unknown-linux-gnu, ppc64le, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	6m 15s
macos-x86_64	4m 35s
linux-cross (powerpc64-unknown-linux-gnu, ppc64, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	6m 3s
linux-cross (arm-unknown-linux-musleabihf, arm)	5m 21s
musllinux (x86_64-unknown-linux-musl)	5m 26s
musllinux-cross (aarch64-unknown-linux-musl, aarch64, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	6m 1s
sdist	4m 50s
windows (x86_64-pc-windows-msvc, x64)	6m 30s
musllinux-cross (armv7-unknown-linux-musleabihf, armv7)	5m 32s
windows (i686-pc-windows-msvc, x86)	6m 30s
musllinux (i686-unknown-linux-musl)	4m 47s
windows (aarch64-pc-windows-msvc, x64)	6m 31s
	1h 43m 26s

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