Ci
* ci: format config (43)
no functional change just add some whitespace and
remove unnecessary name of the checkout step ([`40e8fe2`](https://github.com/abid-mujtaba/testing-fixtures/commit/40e8fe2b360d7cb604b940d5a3dda6062b9857f0))
Fix
* fix: use ruff check and format (44)
* ci: add ruff (check & format), remove black
- ruff check is fantastic
- ruff format is a drop-in replacement for black (in particular the upcoming preview)
the only places where ruff disagrees with black I agree with the former
* ci: configure ruff
- select all rules
- disable the 4 rules globally that conflict with ruff format
- disable certain rules on a per-file basis
- assert is allowed in tests
- we are using print in the unit tests to track execution
* fix: ruff errors
fix all errors detected by ruff after we turned on nearly all the rules
* ci: configure vscode to use ruff
helps find and fix ruff errors ([`c1b1526`](https://github.com/abid-mujtaba/testing-fixtures/commit/c1b1526b1e9eec471888f94d750b82bb414e7a14))