Update to Heasoft 6.33

[zoghbi-a]

This is version 0.6 of heasarc images, which mainly includes updating heasoft to 6.33, plus other changes listed below:

• Update heasoft to v6.33
• Update CIAO to v4.16
• Update SAS to v21.0
• Switch to running jupyter in the base environment, not heasoft
• Add jupytext, and make it a default reader for .md files.
• User conda envs are in persistent/users_conda_envs (defined in condarc).
• Add nb_conda_kernels to handle conda environments (builtin and from the user).
• Fix ghostscript conflict and tcsh initialization in xmmsas
• update ds9 download to use archive links so they persist when new versions are added
• Add back csh initializations
• Add jupyterlab-execute-time
• Add support for a user's bashrc under /home/${user}/workspace/Storage/*/persistent/.bashrc.
• Add JS9