conda: unpin gsl + h5py, loosen sphinx restriction to < 4.x
After addressing issues that will allow us to unpin GSL and h5py as well as sphinx, unpin these in the conda environments for the CI/etc.
Maintenance will be performed on git.ligo.org, containers.ligo.org, and docs.ligo.org on Tuesday 30 April 2024 starting at approximately 9am PDT. It is expected to take around twenty minutes and there will be several periods of downtime throughout the maintenance. Please address any comments, concerns, or questions to the helpdesk.
After addressing issues that will allow us to unpin GSL and h5py as well as sphinx, unpin these in the conda environments for the CI/etc.