chore: bump client spec

[nunogois]

Description

Bumps the client spec to the latest 5.1.0, which includes the "feature_enabled" property, related to #285.

Type of change

Chore / task.

How Has This Been Tested?

Only spec tests are relevant, but ran all of them just in case.

• Unit tests
• Spec Tests
• Integration tests / Manual Tests

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[coveralls]

coverage: 96.892%. remained the same
when pulling b79d290 on chore-bump-client-spec
into eef68c8 on main.