dist: Warn if there are uncommitted changes in the repository
dist: Warn if there are uncommitted changes in the repository

Closes https://github.com/mesonbuild/meson/issues/1977

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