Add a container definition for Rocky Linux 9.3 #63

Job	Run time
build (centos, 7, centos-7, centos-7/Containerfile)	7m 2s
build (rockylinux, 8, rockylinux-8, rockylinux-8/Containerfile)	5m 33s
build (rockylinux, 8.6, rockylinux-8, rockylinux-8/Containerfile-8.6)	6m 52s
build (rockylinux, 8.7, rockylinux-8, rockylinux-8/Containerfile-8.7)	6m 21s
build (rockylinux, 8.8, rockylinux-8, rockylinux-8/Containerfile-8.8)	8m 8s
build (rockylinux, 8.9, rockylinux-8, rockylinux-8/Containerfile-8.9)	4m 51s
build (rockylinux, 9, rockylinux-9, rockylinux-9/Containerfile)	7m 18s
build (rockylinux, 9.0, rockylinux-9, rockylinux-9/Containerfile-9.0)	7m 10s
build (rockylinux, 9.1, rockylinux-9, rockylinux-9/Containerfile-9.1)	6m 15s
build (rockylinux, 9.2, rockylinux-9, rockylinux-9/Containerfile-9.2)	8s
build (rockylinux, 9.3, rockylinux-9, rockylinux-9/Containerfile-9.3)	6m 49s
build (leap, 15, leap, leap/Containerfile.15)	6m 23s
build (leap, latest, leap, leap/Containerfile)	8m 22s
	1h 21m 12s

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