CudaPackage: maintainers are listed in the docstring (#17409)
CudaPackage: maintainers are listed in the docstring (#17409)

fixes #17396

This prevents the class attribute to be inherited and
saves current maintainers from becoming the default
maintainers of every Cuda package.
iulian787/spack,LLNL/spack,LLNL/spack,iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack,iulian787/spack,LLNL/spack,LLNL/spack