Add a "dry-run" release check

[TomAFrench]

Problem

The 0.10.0 release could not be published due to an issue which was only apparent after the release was made.

#240

Proposed solution

To avoid this we can modify the publish.yml workflow to accept a "dry-run" argument which would use cargo publish's --dry-run flag (https://doc.rust-lang.org/cargo/commands/cargo-publish.html#publish-options)

This could be integrated into the release PR's CI, ensuring that it can only be merged if the release can be published.

Alternatives considered

No response

Additional context

No response

Submission Checklist

• Once I hit submit, I will assign this issue to the Project Board with the appropriate tags.

[TomAFrench]

Closing as Cargo doesn't support this for workspaces