ci: run tests using cargo-nextest

[reubenmiller]

Proposed changes

Switch to using cargo-nextest to run the test on the CI Runner. cargo-nextest is already being used in the just test task definition.

Using cargo-nextest will enable individual tests to be configured to automatically retry (e.g. on flaky tests).

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I ran cargo fmt as mentioned in CODING_GUIDELINES
• I used cargo clippy as mentioned in CODING_GUIDELINES
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
486	0	2	486	100	1h20m37.373395999s

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.0%. Comparing base (e7c43aa) to head (d575685).
Report is 3 commits behind head on main.

Additional details and impacted files

see 7 files with indirect coverage changes