rofi: 1.5.0 -> 1.5.1

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

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

These checks were done:

- built on NixOS
- ran `/nix/store/rzgrg39hw115rmgjvp74hha615i3pjdv-rofi-1.5.1/bin/rofi -V` and found version 1.5.1
- ran `/nix/store/rzgrg39hw115rmgjvp74hha615i3pjdv-rofi-1.5.1/bin/rofi -v` and found version 1.5.1
- found 1.5.1 with grep in /nix/store/rzgrg39hw115rmgjvp74hha615i3pjdv-rofi-1.5.1
- directory tree listing: https://gist.github.com/530abc3c76cf94bde0f289edec8973b6