perf: remove SMP system from different host-guest archs

#29 (closed) suggested to try a newer version of QEMU for possible performance upgrades. However, perfromance has declined post update to 9.2.0.

Regardless, a performance boost was found when removing symmetric multiprocessing (SMP) for different host-guest architectures.

Samples

• no -smp
  • qemu 7.2
    • (local) host: amd64 test //.../test-arm64 - average Passed: 287s.
    • (CI) host: arm64 test //.../test-amd64 - 626s
  • qemu 9.2.2
    • host: amd64 test //.../test-arm64 - average Passed: 305s.
• with -smp 4
  • qemu 7.2
    • host: amd64 test //.../test-arm64 - average Passed: 384s.
    • (CI) host: arm64 test //.../test-amd64 - average Passed: 661s, 664
  • qemu 9.2.2
    • host: amd64 test //.../test-arm64 - average Passed: 401s.

qemu 9.2.2 tests take ~15 seconds longer then qemu 7.2 regardless of the smp removal improvement.

• qemu 9.2.2 CI test samples are not included as they produce an error for arm64 host amd64 guest, there are no expected improvements. Therefore, trying to resolve the error would be a waste of effort.

With smp removed for different guest/host archs**:**

• ~100 seconds less for local runs (amd64 host, arm64 guest)
• ~40 seconds less for CI runs (arm64 host, amd64 guest)

Closes #29 (closed).