Fix the dmenu-rs package derivation, which was broken after changes to
the rustPlatform nixpkgs tooling. The issue linked below was
specifically raised on an early version of NixOS 23.05.
This is through no fault of those changes. In fact, the brittle hack in
the dmenu-rs derivation that broke can now be entirely removed because
of the very changes that broke them.
This commit also bumps dmenu-rs from 5.5.1 to 5.5.2. See upstream for
details on the changes.
See https://github.com/NixOS/nixpkgs/issues/222351
See https://github.com/NixOS/nixpkgs/pull/218472
See https://github.com/Shizcow/dmenu-rs
