Minor optimizations

[partiallywritten]

performance = tomfoolery with bit of bullshitting

• perf: Optimize database with slots for performance
• fix: catch asyncio task cancel error
• fix: pass file deleting to thread using asyncio.to_thread
• perf: remove unnecessary f strings and redundant calculations in track_progress function
• chore: publish docker builds manually

[Copilot]

Pull request overview

This PR introduces a micro-optimization to the MongoDB helper by adding __slots__ to the CypherDB class, aiming to reduce per-instance overhead and slightly speed up attribute access in this frequently referenced helper.

Changes:

• Add __slots__ to CypherDB to restrict instance attributes to mongoc and coll_users.
• Add inline commentary explaining (informally) the motivation for the change.

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