BUG: Fix creation of launcher configuration

Remove hack to delete the launcher configuration as part of the build.
The launcher CMake helpers should now be producing correct dependency
information such that the hack is unnecessary, and the dependencies for
the hack were not set up correctly, causing ninja builds to fail to
recreate the configuration on alternating runs (which would prevent
slicer from running).

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23037 3bd1e089-480b-0410-8dfb-8563597acbee