Include missing file in the sdist (#895) #33

Job	Run time
build_sdist	8s
build_no_ext	13s
Build on linux (x86_64 - auto)	2m 18s
Build on linux (aarch64 - musllinux_1_1)	2m 10s
Build on macos (x86_64 - auto)	1m 40s
Build on windows (aarch64 - auto)	3m 24s
Build on macos (aarch64 - auto)	1m 38s
Build on linux (aarch64 - auto)	2m 35s
Build on linux (s390x - auto)	2m 21s
Build on windows (x86_64 - auto)	4m 22s
Build on linux (x86_64 - musllinux_1_1)	2m 8s
Build on linux (ppc64le - auto)	2m 8s
Release	1m 12s
	26m 17s

Provide feedback