updated for ubuntu 22.04 and 24.04

[pitcany]

Hey I updated Stacer for Ubuntu 22.04 and 24.04. Go check it out here and star if you like it!

https://github.com/pitcany/stacer

Some changes:

• Fixed all Qt 5.15+ deprecation warnings (~30 instances across 12 files)
• Updated QtCharts API usage for modern Qt
• Replaced deprecated QDesktopWidget with QGuiApplication::screens()
• Modernized string formatting from sprintf() to QString::number()
• Ready for future Qt 6 migration