Update QEMU base to 8.1

[XVilka]

There are many useful improvements, in target emulation precision, LoongArch support, better portability and TCG plugins.

[vanhauser-thc]

Yes please do a PR :) Andrea did most of the qemuafl stuff but his priorities are now with libafl which has a different approach to qemu integration

[CowBoy4mH3LL]

+1