Fix an issue with the macOS installer from the previous commit.
Fix an issue with the macOS installer from the previous commit.

We should directly run 'dotnet publish' with the Contents/MacOS folder as the output directory, rather than copying things over from a different folder.
The previous approach worked, but did have a leftover warning about the non-existent bin/locale folder.

PintaProject/Pinta,PintaProject/Pinta,PintaProject/Pinta