Tank you Clark,
Now CI went quite smoothly.
But I suppose I hitted another "temporary" bug [1] during :
760 | + dnf install -y python3 python3-pyyaml
761 | CentOS Stream 9 - BaseOS 915 B/s | 3.9 kB 00:04
762 | Errors during downloading metadata for repository 'baseos':
763 | - Downloading successful, but checksum doesn't match. Calculated: 555e83efd3ee35e872b1c6c98d3f4492d02a06b7e48cb82e32795ff7cba5f4d23ba3d67e88d142b7c4b4c48b1c421ad9fb3b58668a320f06c5ff75da1372a5e4(sha512) Expected: b0039a09d28e22148f55ea1551a3d47beb9e9b647dfb453f6dca4075a4d011fa238d7e704a1e22b3923cb8033845ef6993e3512d3ee20e293897e9c053b2e628(sha512)
764 | Error: Failed to download metadata for repo 'baseos': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
May I retry again later (Gerrit recheck tomorrow for example), or as far as you know there are some issues in the OpenStack YUM repository mirrors that prevent DNF operations?