Pick arm64 also for the Workflow.

[ikitayama]

This can be pulled when major changes to the run_qemu.sh script are pulled.

[marc-hb]

https://github.com/pmem/run_qemu/actions/runs/14211988166/job/39863438595?pr=142

This runs make defconfig=arm64 yet the kernel does not seem to be cross-compiled. More seems required.

  CC      kernel/capability.o
  AR      arch/x86/net/built-in.a
  CC      security/keys/encrypted-keys/encrypted.o
  CC      fs/squashfs/dir.o
  AR      arch/x86/platform/intel/built-in.a
  AR      arch/x86/platform/intel-mid/built-in.a
  AR      arch/x86/platform/intel-quark/built-in.a
  AR      arch/x86/platform/olpc/built-in.a
  AR      arch/x86/platform/scx200/built-in.a
  AR      arch/x86/platform/ts5500/built-in.a
  AR      arch/x86/platform/uv/built-in.a
  AR      arch/x86/platform/built-in.a
  CC      arch/x86/purgatory/purgatory.o
  AS      arch/x86/purgatory/stack.o
  CC      fs/squashfs/export.o
  AS      arch/x86/purgatory/setup-x86_64.o
  CC      arch/x86/purgatory/sha256.o