Add CentOS Stream 9 (again) #21

Job	Run time
ci / build-test (centos-stream9, centos.dockerfile)	3m 45s
ci / build-test (fedora-39, fedora.dockerfile)	3m 46s
ci / build-test (fedora-40, fedora.dockerfile)	2m 54s
ci / build-test (fedora-41, fedora.dockerfile)	2m 12s
ci / build-test (debian-12, debian.dockerfile)	2m 33s
ci / build-test (debian-13, debian.dockerfile)	2m 55s
ci / build-test (ubuntu-22.04, debian-old.dockerfile)	1m 13s
ci / build-test (ubuntu-24.04, debian.dockerfile)	2m 9s
ci / build-test (ubuntu-24.10, debian.dockerfile)	3m 23s
ci / build-test (archlinux, archlinux.dockerfile)	3m 27s
ci / build-test (opensuse-tumbleweed, suse.dockerfile)	2m 38s
ci / build-test (opensuse-leap-15.6, suse.dockerfile)	2m 46s
tag / tag	3s
	33m 44s

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