ci: Fix failures in vs2019 jobs on Azure
ci: Fix failures in vs2019 jobs on Azure

pip warns about being out of date and powershell interprets that as an
error because reasons.

Found in https://github.com/mesonbuild/meson/pull/5687#issuecomment-514268525

becm/meson,becm/meson,QuLogic/meson,pexip/meson,mesonbuild/meson,jpakkane/meson,mesonbuild/meson,becm/meson,jpakkane/meson,jpakkane/meson,jpakkane/meson,QuLogic/meson,becm/meson,becm/meson,mesonbuild/meson,QuLogic/meson,pexip/meson,QuLogic/meson,jpakkane/meson,mesonbuild/meson,pexip/meson,QuLogic/meson,jpakkane/meson,QuLogic/meson,becm/meson,becm/meson,QuLogic/meson,QuLogic/meson,pexip/meson,jpakkane/meson,mesonbuild/meson,QuLogic/meson,mesonbuild/meson,becm/meson,mesonbuild/meson,pexip/meson,pexip/meson,mesonbuild/meson,becm/meson,mesonbuild/meson,pexip/meson,becm/meson,jpakkane/meson,pexip/meson,pexip/meson,mesonbuild/meson,jpakkane/meson,pexip/meson