frontend: Use same base theme on Win 10/11

[Warchamp7]

Description

Forces Windows 11 to use the windowsvista base theme.

Fixes some weird padding issues on Windows 11 on the current Qt version.

Fixes #13598

Motivation and Context

We override pretty much every aspect of the style via our stylesheet so this just ensures Win 10 and Win 11 both start from the same base appearance, instead of the system default Qt style (windowsvista on Win10, windows11 on Win11)

How Has This Been Tested?

Compiled and ran on my Windows 11 laptop. Confirmed that the extra padding in list views is gone.

Also compiled and ran on my Windows 10 machine with the style set to windows11 instead, which caused the excessive padding on my Windows 10 machine.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have read the contributing document.
• My code has been run through clang-format.
• My code follows the project's style guidelines
• My code is not on the master branch.
• My code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[RytoEX]

This seems a bit of a kludge. The windowsvista style is less maintained than the windows11 from a glance at the commit history, and there are some behavior differences between the two (progress bar text rendering, I think). I would not be surprised if some day Qt removes the windowsvista style, so we should report this as a QTBUG.

I would be curious if this is still an issue: https://qt-project.atlassian.net/browse/QTBUG-142408

[Warchamp7]

This seems a bit of a kludge. The windowsvista style is less maintained than the windows11 from a glance at the commit history, and there are some behavior differences between the two (progress bar text rendering, I think). I would not be surprised if some day Qt removes the windowsvista style, so we should report this as a QTBUG.

I would be curious if this is still an issue: https://qt-project.atlassian.net/browse/QTBUG-142408

The windows style which is based off windows 95 still exists and would work just as well too. I'm not sure why you'd expect the vista theme to have a more active commit history than the windows11 theme, which is clearly still a work in progress :P