gitlab-ci: Only use one process in Windows jobs for compilation

The Windows jobs are currently aborting at weird places - and
there's the suspicion that it's due to memory constraints in
the Windows containers. Let's switch to single-threaded compilation
to decrease the pressure on the memory load, and to make the
job more deterministic for further investigations.

Message-Id: <20220825193323.104768-1-thuth@redhat.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

.gitlab-ci.d/windows.yml

@@ -61,7 +61,7 @@ msys2-64bit:
   - .\msys64\usr\bin\bash -lc './configure --target-list=x86_64-softmmu
       --enable-capstone --without-default-devices'
   - .\msys64\usr\bin\bash -lc "sed -i '/^ROMS=/d' build/config-host.mak"
-  - .\msys64\usr\bin\bash -lc 'make -j2'
+  - .\msys64\usr\bin\bash -lc 'make'
   - .\msys64\usr\bin\bash -lc 'make check'
 
 msys2-32bit:
@@ -94,5 +94,5 @@ msys2-32bit:
   - mkdir output
   - cd output
   - ..\msys64\usr\bin\bash -lc "../configure --target-list=ppc64-softmmu"
-  - ..\msys64\usr\bin\bash -lc 'make -j2'
+  - ..\msys64\usr\bin\bash -lc 'make'
   - ..\msys64\usr\bin\bash -lc 'make check'