RHEL moved from bugzilla to Jira see the RHEL project at issues.redhat.com. I didn't find an official announcement, only this thread on Fedora Devel mailing list announcing the move in 2022.
CentOS Wiki now also points to Red Hat Jira for reporting bugs against CentOS Stream 8 to 10.
Edit: An update about the migration was posted on Fedora Devel mailing list with more details about reporting new bug reports for RHEL/CentOS and migrating existing reports to Jira:
All new issues found or desired in RHEL (Or CentOS Stream) need to be filed on issues.redhat.com. It's no longer possible to create new BZs for current RHEL (7 through 9) releases. Over the next few weeks, most RHEL BZs will be migrated to tickets in the RHEL project on issues.redhat.com. The BZs that are migrated will be closed with resolution MIGRATED and a pointer to the Jira issue included in the external links section of each