CI task definition update process is broken

[lydiascarf]

Yeah, the part of the build script that updates the batch job definition worked on Jenkins but doesn't work on Github Actions because it relies on a configured AWS profile, which we don't have set up there. So the options, from simplest to most involved, would be

• Add a condition to skip that step in CI. That would get the CI builds working except for running analysis jobs, so we'd need to remember to do a manual deploy to staging any time we want to run the analysis there (which isn't that common. Usually we only do that when we're getting ready to do a release.)
• Configure an AWS profile on Github Actions so it'll work with the job update script as-is. We didn't do this when we switched to Github Actions, but I think it's possible. Maybe even not that difficult. Or it might be a layer of configuration that we don't want to deal with. I'm not sure.
• Bring the batch job definition update into Terraform. I believe it was handled separately during initial development because Terraform didn't have full support for Batch actions at that point, but I'm sure it does by now. This would produce the best long-term outcome, since there wouldn't be a separate script or process at all, the Batch changes would just be applied along with the other Terraform actions.
  -- @KlaasH

This commit represents the current workaround we used to update staging: 243cd79