Refresh `github_actions.free_disk_space` and add to schema

[jakirkham]

• Update github_actions.free_disk_space to match azure.free_disk_space
• Add github_actions.free_disk_space to schema (was missing before)
• Run python conda_smithy/schema.py to update associated files

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Checklist

• [x] Added a news entry

Fixes https://github.com/conda-forge/conda-smithy/issues/1880

[jakirkham]

Testing in PR: https://github.com/rapidsai/xgboost-feedstock/pull/53

Edit: Has already passed the clean up stage. So this appears to work

[jakirkham]

Thanks Matt! 🙏