Release Candidates should not publish documentation

[robons]

The current csvcubed release process automatically deploys the whl to pypi and the documentation to the relevant GitHub pages location.

Unfortunately, when a release candidate is published, it automatically overwrites the live documentation with the docs for this release candidate, which may introduce inconsistencies and state incorrect information which could confuse external users of csvcubed.

As part of this ticket, you should alter the csvcubed release pipeline so that the documentation is not released for version tags matching the release candidate pattern (or alternatively GitHub releases which are marked as pre-releases.

The area of code you'll need to change is here.