Update ncdu version

[aidanheerdegen]

The latest version of ncdu available in spack-packages is 1.19

https://github.com/ACCESS-NRI/spack/blob/releases/v0.22/var/spack/repos/builtin/packages/ncdu/package.py#L22

the same is true of upstream

https://github.com/spack/spack-packages/blob/develop/repos/spack_repo/builtin/packages/ncdu/package.py#L23

The most recent C version is 1.22

https://dev.yorhel.nl/ncdu

If we wanted a more up to date version we would need to create an issue and PR in upstream spack.