Created attachment 154597 [details]
Screenshot: unused "Open Widgets" entry, splitting the list of documents in half

The new settings and welcome page for new tabs introduced an "Open Widgets" root element in the sidebar, holding these children. Unfortunately when there are none, it is still displayed and splits the open documents list in half.

STEPS TO REPRODUCE
1. Have a sidebar with the open documents as a tree
2. Have a recent version of kate

OBSERVED RESULT
"Open Widgets" entry that can't be disabled and splits the open documents in half, even when not needed

EXPECTED RESULT
No such thing

From an UX perspective I'd recommend to
- Hide that element completely (not disable/grey out) when there are no children
- When there are, ensure that it is either on top or at bottom, but does not split the list of open documents in half

ADDITIONAL INFORMATION

Kate 22.12.0 from Fedora RPMs

Operating System: Fedora Linux 37
KDE Plasma Version: 5.26.4
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.7
Kernel Version: 6.0.12-300.fc37.x86_64 (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i5-8365U CPU @ 1.60GHz
Memory: 15.3 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 620
Manufacturer: LENOVO
Product Name: 20NQS5TD01
System Version: ThinkPad X390 Yoga