Tracking Issue for "Crate Deletions"

[Turbo87]

This is a tracking issue for the RFC "crates.io: Crate Deletions" (rust-lang/rfcs#3660).

About tracking issues

Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.
Discussion comments will get marked as off-topic or deleted.
Repeated discussions on the tracking issue may lead to the tracking issue getting locked.

Steps

• Implement crate deletion API endpoint
• Implement crate deletion user interface
• Implement version deletion API endpoint
• Implement version deletion user interface
• Update https://crates.io/policies to no longer mention that "Crate deletion by their owners is not possible"

Unresolved Questions

• Should names of deleted crates be blocked so that they can't be re-used?
• Should deleted versions be blocked from being re-uploaded?
• Should we keep and mark deleted versions in the index?