ci: set kvm permissions for GHA QEMU jobs

ci: set kvm permissions for GHA QEMU jobs

The image used by GitHub-hosted runners changed the default kvm device
permissions recently rendering us no longer able to start guest VMs. The
error message:

Could not access KVM kernel module: Permission denied
qemu-system-x86_64: failed to initialize kvm: Permission denied

Working run: https://github.com/fiotestbot/fio/actions/runs/14186873066
Failed run: https://github.com/fiotestbot/fio/actions/runs/14211189491

Explicitly give the GitHub Actions runner user permission to access the
/dev/kvm device following the guide at

https://github.blog/changelog/2024-04-02-github-actions-hardware-accelerated-android-virtualization-now-available/

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>