Add Brave browser to IncognitoBrowser.cpp so that links open in a private tab

[nrpHD]

Checklist

• [X] I'm reporting a problem with Chatterino
• [X] I've verified that I'm running the most recent nightly build or stable release
• [X] I've looked for my problem on the wiki
• [X] I've searched the issues and pull requests for similar looking reports

Describe your issue

When setting the Brave browser as your default browser, clicking a link will open it in non-incognito mode.

It should behave the same as on e.g. Firefox, where the link is opened in a private tab. It should only open in non-incognito mode via right click -> open link.

My assumption is that this can be achieved by adding Brave to the list of browser in the IncognitoBrowser.cpp file.

Screenshots

OS and Chatterino Version

Chatterino 2.5.1 (commit eafcb94) built with Qt 6.5.0, Running on Windows 11 Version 23H2, kernel: 10.0.22631