Please check in `Cargo.lock`

## What problem does this solve or what need does it fill?

`Cargo.lock` ensures that any bevy commit that passes CI that be built locally, even after (allegedly) semver-compatible dependency updates are released. This helps with bisecting issues in bevy or in Rust that affect bevy.

## What solution would you like?

`Cargo.lock` should be checked into the repository. Tools like dependabot can help with regularly running `cargo update`.

## What alternative(s) have you considered?

Leave it out of the repository.

## Additional context

There is some arguably outdated advice out there that states that only binary crates should check in the lockfile, but the more modern position is that the lockfile is useful for library crates as well as binary crates, as the reproducibility is valuable for both.

Start by reading the repository’s Rust workspace setup and the issue’s rationale for checking in Cargo.lock. Check whether Cargo.lock is present and review the project’s guidance on dependency updates; done means the lockfile is checked in as requested, with the resulting repository state consistent with the build.

Written by the indexing model from the issue text.