Make QCoDeS validator of attenuation conditional. Remove upper bound from _set_out_att

Description

qblox_instruments side of the fix for #172

Type

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Code refactoring (only refactoring of existing code, without new functionality)

Issue(s)

Related MRs

https://gitlab.com/qblox/packages/software/pulsar_src/-/merge_requests/263

Testing

Notes

Merge checklist

• Cleaned up code (correct alligment/spacing/code-style, no dead code, etc).
• Merge request targets development branch.
• Assigned assignee (you) and reviewers (team-members).
• Merge request has been reviewed by at least one team-members.
• All pipelines pass, including manually triggered ones.
• If merging a repository with a release package, updated appropriate CHANGELOG.md:\
  • PULSAR_QxM, CLUSTER_MM, QBLOX_INSTRUMENTS: file in same repository\
  • CLSUTER_QxM: file in CLUSTER_MM repo