Use `ArcStr` for marker values #785

Job	Run time
macos-x86_64	15m 58s
sdist	10m 13s
linux (x86_64-unknown-linux-gnu)	7m 57s
macos-aarch64	18m 0s
linux (i686-unknown-linux-gnu)	11m 0s
linux-powerpc (powerpc64le-unknown-linux-gnu, ppc64le, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	11m 3s
linux-powerpc (powerpc64-unknown-linux-gnu, ppc64, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	11m 14s
windows (x86_64-pc-windows-msvc, x64)	15m 4s
windows (i686-pc-windows-msvc, x86)	14m 42s
linux-arm (aarch64-unknown-linux-gnu, aarch64, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	11m 15s
linux-arm (armv7-unknown-linux-gnueabihf, armv7)	10m 25s
linux-s390x (s390x-unknown-linux-gnu, s390x)	14m 57s
linux-arm (arm-unknown-linux-musleabihf, arm)	10m 20s
musllinux (x86_64-unknown-linux-musl)	10m 37s
musllinux (i686-unknown-linux-musl)	9m 47s
musllinux-cross (aarch64-unknown-linux-musl, aarch64, -e JEMALLOC_SYS_WITH_LG_PAGE=16)	11m 4s
musllinux-cross (armv7-unknown-linux-musleabihf, armv7)	10m 30s
	3h 24m 6s

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