gitlab-ci: Cover SPICE in the MSYS2 job

gitlab-ci: Cover SPICE in the MSYS2 job

Include the mingw-w64-x86_64-spice package so SPICE is covered:

  C compiler for the host machine: cc -m64 -mcx16 (gcc 12.2.0 "cc (Rev10, Built by MSYS2 project) 12.2.0")
  ...
  Run-time dependency spice-protocol found: YES 0.14.4
  Run-time dependency spice-server found: YES 0.15.1

In particular this would have helped catching the build issue
reported as https://gitlab.com/qemu-project/qemu/-/issues/1553:

  [1851/5253] Compiling C object libcommon.fa.p/ui_spice-core.c.obj
  FAILED: libcommon.fa.p/ui_spice-core.c.obj
  ../ui/spice-core.c: In function 'watch_remove':
  ../ui/spice-core.c:152:5: error: implicit declaration of function 'qemu_close_to_socket' [-Werror=implicit-function-declaration]
  152 |     qemu_close_to_socket(watch->fd);
      |     ^~~~~~~~~~~~~~~~~~~~
  ../ui/spice-core.c:152:5: error: nested extern declaration of 'qemu_close_to_socket' [-Werror=nested-externs]

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230322135721.61138-2-philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>