Sync crate owners on crates.io

[Kobzol]

This PR implements sync of crate ownership on crates.io (#2134 (review)). It allows configuring Rust teams that own a given crate on crates.io, and synces the team ownership on crates.io.

It does not yet remove user ownership for other accounts than rust-lang-owner; we first need to transition some crates to team ownership before that.

Best reviewed commit-by-commit.

CC @Mark-Simulacrum

[github-actions]

Dry-run check results

[WARN  sync_team] sync-team is running in dry mode, no changes will be applied.
[INFO  sync_team] synchronizing crates-io
[INFO  sync_team] synchronizing github

[marcoieni]

merging this PR will remove other owners, right?
Such as the ones in https://crates.io/crates/annotate-snippets
Or am I misunderstanding?

[Kobzol]

I see, I didn't realize we still have crates with individual owners. Ok, then that logic will have to wait, and I'll rework this PR slightly.

[rustbot]

rust_team_data/src/v1.rs has been modified, it is used (as a git dependency) by multiple sub-projects like triagebot, the www.rust-lang.org website and others.

If you are changing the data structures, please make sure that the changes are not going to break serde deserialization (adding a field is fine; removing or renaming a field isn't).

If you must do a breaking change to the format, make sure to coordinate it with all the users of the rust_team_data crate.

[Kobzol]

Ok, new version, now it should do complete sync of team owners.

[Mark-Simulacrum]

We should probably contact crate owners that would get removed with this to let them know, maybe confirm they're ok with it.

[Kobzol]

In the current state, this would only remove team, not user, owners, and it should not actually remove anyone, as long as I backfilled the teams currently. We only have 5 repos with crates tracked in team currently.

[Kobzol]

Rebased.

[Kobzol]

Removed invitation of rust-lang-owner, as I realized that it doesn't make sense, it already has to own these crates, otherwise it couldn't access them in the first place. That also saves us from hardcoding rust-lang-owner in the source code.

[Kobzol]

Rebased over the recent changes to the crates.io syncing logic. Unlike trusted publishing, the dry-run should actually work here (still has to be done in a separate PR though).