adding method for qemu build from Intel-distribution-of-QEMU

[tathagax]

Adds a standalone workflow that builds QEMU directly from the Intel Intel-distribution-of-QEMU git branch (10.2.1-gfx-sriov, pinned commit faa368fe92…) instead of the download.qemu.org tarball .

Highlights:

1. Builds QEMU straight from the git branch (which already carries all 27 SR-IOV/GTK commits) .
2. Fetches the upstream release tarball only to supply the pc-bios firmware blobs and lcitool submodule content a bare checkout lacks.
3. Handles the known build : pip3 install meson pycotap (offline mkvenv) and copying pc-bios/* before meson setup.
4. Runs on workflow_dispatch (manual) with a disable_cache input (default false).