test: Auto-redact file number
This is from <https://github.com/rust-lang/cargo/pull/14096#discussion_r1648889843>.
Although the number of files in `cargo package` is important,
we have `validate_crate_contents` and `validate_upload_with_contents`
that verify the exact contents.
Redacting `Packaged` status should be fine.
Add local registry overlays
This PR adds (private to cargo internals) support for local registry overlays, in which you can locally pretend to add packages to remote registries; the local packages will have the same source ids as the remote registry that you're overlaying.
There are two ways to set up these overlays: programmatically using `GlobalContext::local_overlays` and through the `__CARGO_TEST_PACKAGE_CONFUSION_VULNERABILITY_DO_NOT_USE_THIS` environment variable. You can't set up these overlays with `.cargo/config`.
The motivation for this is [packaging workspaces](https://github.com/rust-lang/cargo/issues/10948). When we're packing a workspace, we'd like to be able to pretend (for lockfile generation and verification) that some workspace packages are already published even though they aren't.
While this is noisy and hides other deprecations, I figured deprecations would
make it easier for people to discover what tasks remain and allow us to
divide and conquer this work rather than doing a heroic PR.
In theory, this will be short lived and we'll go back to seeing
deprecations in our tests.
refactor: Transition direct assertions from cargo-test-support to snapbox
### What does this PR try to resolve?
Cargo has a bespoke testing framework for functional tests
- Extra stuff for us to maintain
- Don't leverage benefits from contributions related to other projects
- Less incentive to be thoroughly documented
UI tests are written using snapbox. The latest release of snapbox (#13963) was geared at supporting cargo's needs in the hope that we can consolidate on testing frameworks.
Besides having a single set of semantics, benefits we'd gain include
- Updating of test snapshots
- Fancier redacting of test output (e.g. #13973)
This is the first incremental step in this direction. This replaces direct assertions with snapbox assertions. This still leaves all of the CLI output assertions. These will be done incrementally.
### How should we test and review this PR?
### Additional information
They are still nominally gzipped, but using `Compression::none()` makes
them consistent even across zlib and zlib-ng, and this fixes checksum
differences in the testsuite. There is a one-time update of all those
checksums to catch up with this change though.
