The plasma package kinfocenter is not present in EPEL 10 and cannot be installed and therefore there is no 'About this system' window in plasma settings. It is present in EPEL 9 and the Fedora repos.
I've logged an issue in the EPEL bug tracker as well.
https://pagure.io/epel/issue/314
This is being worked in the KDE SIG ticket https://pagure.io/fedora-kde/SIG/issue/613
Although kinfocenter builds in epel10, it is not installable yet due to missing runtime package.
Metadata Update from @tdawson: - Issue assigned to tdawson
kinfocenter is on it's way for CentOS Stream 10 https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2025-e7b251aaf9 https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2025-4dad26bc67
This has been fixed in this quarters Live images, that have been released..
Metadata Update from @tdawson: - Issue status updated to: Closed (was: Open)