Cockpit depends on the Patternfly library and as v5 no longer gets updates we should make sure to upgrade to v6 to be aligned with the latest updates and reconsider our CSS overrides. This will help with long-term sustainability and reduce overhead when updating Patternfly and CSS related dependencies.

This is primarily a change with Cockpit Core as plugins can adapt the new styling when they're ready. We will however need to update all of the supported plugins we support, such as cockpit-files, cockpit-machines, etc.

Acceptance Criteria

• Document majority of changes that need to happen before migration period starts
• Migration period is determined and agreed upon in advance
• Works in both light and dark theme
• All core pages work as expected
• All Cockpit project plugins work as expected
• Mobile view works as expected

Notes

• Two team members serve as approvers for when an upgrade has flaws (glesage@redhat.com and rhn-engineering-mpitt)