Fix invalid YAML merges in ci config

See merge request !131770



Merged-by: David Dieulivol <ddieulivol@gitlab.com>
Approved-by: David Dieulivol <ddieulivol@gitlab.com>
Reviewed-by: David Dieulivol <ddieulivol@gitlab.com>
Co-authored-by: Arran Walker <ajwalker@gitlab.com>