Mef/zext phi cleanup

[cqc-melf]

Description

I have tried to split this PR into useful commits to make it easier to review: regenerate QIR test files Contains only the regeneration of the QIR files, this is quiet a lot and not really relevant to review.

clean up tests In this commit, I have cleaned up the tests and reorganised profile and non profile tests together in on file.

fix bug in phi node generation, add set_bit via zext This is the most relevant to review, this fixes a problem with the phi nodes and add the new set_bit via zext.

update version, changelog, pytket Contains general cleanup and preparation for the next release candidate.

Related issues

Please mention any github issues addressed by this PR.

Checklist

• [x] I have performed a self-review of my code.
• [x] I have commented hard-to-understand parts of my code.
• [x] I have made corresponding changes to the public API documentation.
• [x] I have added tests that prove my fix is effective or that my feature works.
• [x] I have updated the changelog with any user-facing changes.