Create a new release with each new build

[phargogh]

While the meat of the devstack is complete (a docker container, with container tags), there are several QOL improvements that we could do to make it easier to use. I think it would be helpful to create a new release with each new build. This would enable:

1. We would tag the git repository with the same datestamp tag (YYYY-MM-DD) as the docker container, which would make it easier to link a specific container back to the source code.
2. Creating a new release gives us a chance to update the text of the release body with the specific instructions, including the correct SHA digest, for that specific container and also a report of all the packages included in this release for later reference.
3. Creating a new release allows us to pre-build a singularity container and attach it as a release artifact, provided that the file is less than 2GB in size. If the devstack image exceeds that, we'll need to rethink this approach, trim the size of the container, or else host the container somewhere else, like on GCS.

[phargogh]

I just ran the following on sherlock on the latest devstack tag (currently at 2023-03-24, sha256:f4d6caee97b6fac7535bf9fd8bc53dbb76c87260aa86eed11532c78aeb246c05), and am relieved to see that even though we're installing a whole lot of dependencies (including GDAL), the singularity image size is under 1GB:

[sh03-ln02 login ~]$ srun apptainer pull $SCRATCH/natcap-devstack.sif docker://ghcr.io/natcap/devstack:latest
[sh03-ln02 login ~]$ du -h $SCRATCH/natcap-devstack.sif
873M	/scratch/users/jadoug06/natcap-devstack.sif

[dcdenu4]

This seems like a nice clean approach to me!