Update Qt to 6.8.1

[thedjnK]

Qt 6.8.1 will be released on 29/11/2024, all system toolchains should be rebuilt for this

• [ ] Windows toolchain rebuilt
• [ ] Linux toolchain rebuilt
• [ ] mac toolchain rebuilt
• [ ] AuTerm Windows builds successfully
• [ ] AuTerm Linux builds successfully
• [ ] AuTerm mac builds successfully
• [ ] AuTerm Windows runs successfully
• [ ] AuTerm Linux runs successfully