datasets_download try/catching the git-lfs prune for versions that do not support -f

[jackkolb]

This commit adds a try/catch in the datasets_download.py script around the git lfs prune -f --recent call to re-run the command without the -f switch. While users can specify --no-prune in the data loader command, that workaround should not be necessary.

Motivation and Context

Some common git-lfs versions (e.g., 2.9.2 which Ubuntu 20.04 runs) do not support the -f flag on git lfs prune. This change wraps the git lfs prune -f --recent call in a try/catch for compatibility and a simpler user experience. Issue #2172 asks about this.

How Has This Been Tested

I tested loading a dataset using git-lfs version 2.9.2, which previously broke due to the assumed -f switch. I used the command:

python -m habitat_sim.utils.datasets_download --uids rearrange_task_assets --data-path data

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes.
• All new and existing tests passed.