Fix a broken build

[chosungmann]

Checklist

• I have read the Contributor Guide
• I have read and agree to the Code of Conduct
• I have added a description of my changes and why I'd like them included in the section below

Description of Changes

The tip of tree currently breaks at:

    ...
       Compiling sentry-types v0.31.8
       Compiling sentry-core v0.31.8
       Compiling sentry-contrib-breakpad v0.8.0
    error[E0599]: no function or associated item named `new_v4` found for
      struct `Uuid` in the current scope --> src/shared.rs:26:46
       |
    26 | .unwrap_or_else(types::Uuid::new_v4),
       |                              ^^^^^^
       |                              |
       | function or associated item not found in `Uuid`

This is due to the fact that a breaking change was introduced at getsentry/sentry-rust#614.

Related Issues

List related issues here

[MarijnS95]

For this to work well we should follow up on #22 (comment) and:

1. Publish a patch release of sentry-contrib-rust with the proper maximum-version bound;
2. Yank the older patch release(s) that still have this unbounded version;
3. Bump the minimum like you did here in a new release (breaking?) release.

[MarijnS95]

Also, because this is a non-breaking release for sentry, they probably shouldn't have made such a breaking change in the first place. It's a bit of a grey area since they're removing a feature from a dependency, but types from that dependency are publicly reexported.

[Jake-Shadle]

Thanks!