Automate archival snapshot uploads

[lemmih]

Issue summary

We maintain archives of diff snapshots (one per 3,000 epochs) and lite snapshots (one per 30,000 epochs) for both mainnet and calibnet. See https://forest-archive.chainsafe.dev/list/calibnet/diff and https://forest-archive.chainsafe.dev/list/calibnet/lite.

Right now, we manually generate and upload new files occasionally. The steps are roughly:

1. Sync with latest lite+diff snapshots.
2. Export a large master snapshot covering, say, 30,000 epochs.
3. Generate diffs and lite snapshots from the master snapshot. Eg. forest-tool archive export ...
4. Upload snapshots.
5. Repeat as necessary.

This process has to be automated. Open questions:

• Should this happen on a DO droplet or on Archie/Fuzzy?
• How often should the archives be updated? Once per day or once per 10-day?

Other information and links

Archival diffs: https://forest-archive.chainsafe.dev/list/calibnet/diff
Archival lites: https://forest-archive.chainsafe.dev/list/calibnet/lite