There's a closed pull request on the void-packages repository

New package: singularity-3.7.1
https://github.com/void-linux/void-packages/pull/28129

Description:
#### General
- [x] This is a new package and it conforms to the [quality requirements](https://github.com/void-linux/void-packages/blob/master/Manual.md#quality-requirements)

#### Have the results of the proposed changes been tested?
- [x] I use the package proposed for inclusion on a regular basis and confirm it works for me

The tests require `sudo`, so they are disabled. To start an interactive Alpine container, run installation 
```
$ singularity pull alpine
$ singularity run alpine_latest.sif
``` 

#### Does it build and run successfully? 
- [x] I built this PR locally for my native architecture, (x86_64)