qt6Packages.qtools - binaries are in .dev output

[peterhoeg]

Describe the bug

qt6Packages.qttools contains a number of tools, that are also useful outside of package building. I am specifically thinking about qdbus and qdbusviewer.

In qt5, they are part of qttools.bin but with qt6, they are in qttools.dev which means bringing them into your environment causes a long list of other .dev dependencies to be brought in.

Cc: @NickCao

Reference: #202293

[NickCao]

I found that these two kind of tools are declared in cmake as qt_internal_add_app or qt_internal_add_tool, there must be a way to programmatically separate them.

[NickCao]

The current behavior is due to us unconditionally moving $out/bin to $dev/bin, while in qt-5 only the devtools are cherry picked:

nixpkgs/pkgs/development/libraries/qt-6/qtModule.nix

Line 36 in 878cb61

for dir in bin libexec mkspecs

[NickCao]

Also partly due to my cmake patch determining that all directory ending in bin should go to the dev output.