singularity: 2.4.2 -> 2.4.5

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

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

These checks were done:

- built on NixOS
- ran `/nix/store/893zy5r9ih8lp9p24s9l198jdjdwadj4-singularity-2.4.5/bin/singularity -h` got 0 exit code
- ran `/nix/store/893zy5r9ih8lp9p24s9l198jdjdwadj4-singularity-2.4.5/bin/singularity --help` got 0 exit code
- ran `/nix/store/893zy5r9ih8lp9p24s9l198jdjdwadj4-singularity-2.4.5/bin/singularity help` got 0 exit code
- ran `/nix/store/893zy5r9ih8lp9p24s9l198jdjdwadj4-singularity-2.4.5/bin/singularity -v` and found version 2.4.5
- found 2.4.5 with grep in /nix/store/893zy5r9ih8lp9p24s9l198jdjdwadj4-singularity-2.4.5
- directory tree listing: https://gist.github.com/f42298f39e3c1c4832de9817cc1fc5bf