dunst: 1.3.1 -> 1.3.2

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/dunst/versions.

These checks were done:

- built on NixOS
- ran ‘/nix/store/41nqz94x6682ylch4vhg5pca977ffsd0-dunst-1.3.2/bin/dunst -h’ got 0 exit code
- ran ‘/nix/store/41nqz94x6682ylch4vhg5pca977ffsd0-dunst-1.3.2/bin/dunst --help’ got 0 exit code
- ran ‘/nix/store/41nqz94x6682ylch4vhg5pca977ffsd0-dunst-1.3.2/bin/dunst -v’ and found version 1.3.2
- ran ‘/nix/store/41nqz94x6682ylch4vhg5pca977ffsd0-dunst-1.3.2/bin/dunst --version’ and found version 1.3.2
- found 1.3.2 with grep in /nix/store/41nqz94x6682ylch4vhg5pca977ffsd0-dunst-1.3.2
- directory tree listing: https://gist.github.com/e6f68836d92d5855b650ece5004da126