pin qiskit-aqt-provider to version 1.5.0

[trvto]

Description

Tests fail with version >=1.6.0 because it seems they don't handle dependencies correctly. Probably need to create an issue on their end. But could be addressed in our own code. This is the fix for now.

Going forward probably best to pin to a specific version anyway.

Related issues

Resolves #106

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.

[cqc-melf]

Maybe add this to the changelog?