Description:
When using Libreoffice 24.2.1 on Wayland with a fractionally scaled output (does not matter whether multiple monitors exist, also occurs without external monitors attached) with the Qt6 or KF6 VCL Plugins, the toopbars are scaled far too large. Scaling works fine with the Qt5 or KF5 VCL Plugins.

The bug occurs for me in Plasma 6 with the default VCL plugin and in Sway 1.9 with the VCL plugin forced using SAL_USE_VCLPLUGIN=qt6

This is possibly related to Bug https://bugs.documentfoundation.org/show_bug.cgi?id=141578 but that one explicitly called out multi-monitor setups and applied to both KF5 and KF6. 

Steps to Reproduce:
1. Use a Wayland Compositor that supports Fractional Scaling (Sway 1.9, Plasma 6, etc)
2. Change your monitor to be fractionally scaled (e.g. 125%)
3. run SAL_USE_VCLPLUGIN=kf6 lowriter or SAL_USE_VCLPLUGIN=qt6 lowriter
4. Observe the huge toolbar compared to the titlebar drawn by the compositor

Actual Results:
Toolbar is far too large (around twice as large as it should be)

Expected Results:
Toolbar is scaled accordingly and doesn't appear larger


Reproducible: Always


User Profile Reset: No

Additional Info:
This bug was originally reported downstream in the Arch Linux Bug Tracker:

https://gitlab.archlinux.org/archlinux/packaging/packages/libreoffice-fresh/-/issues/2