Auto merge of #14149 - eth3lbert:snapbox-registry, r=weihanglo

test: migrate registry and registry_auth to snapbox

### What does this PR try to resolve?

Part of #14039.

Migrate following to snapbox:

- `tests/testsuite/registry.rs`
- `tests/testsuite/registry_auth.rs`

### Additional information

Parameterize shared logic over inline snapshots to prevent the content from being appended multiple times in `str![]` when it's called multiple times within a reusable function.

Big thanks to `@weihanglo` for helping me out!

Author: bors