feat: add pytest-randomly as tests dependency (#47)

# Description

This PR add `pytest-randomly` as dependency so our test suite is
executed in a random way.

After this change a new `Using --randomly-seed=2880304302` line will
appear when tests are executed, showing the random seed that it's used
in the case that you need to reproduce the order and debug some error.

Refs #44 

**Type of change**

(Please delete options that are not relevant. Remember to title the PR
according to the type of change)

- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Refactor (change restructuring the codebase without changing
functionality)
- [ ] Improvement (change adding some improvement to an existing
functionality)
- [ ] Documentation update

**How Has This Been Tested**

(Please describe the tests that you ran to verify your changes. And
ideally, reference `tests`)

- [x] Tests should be passing.

**Checklist**

- [ ] I added relevant documentation
- [ ] follows the style guidelines of this project
- [ ] I did a self-review of my code
- [ ] I 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
- [ ] I filled out [the contributor form](https://tally.so/r/n9XrxK)
(see text above)
- [ ] I have added relevant notes to the CHANGELOG.md file (See
https://keepachangelog.com/)

pyproject.toml

@@ -101,6 +101,7 @@ test = [
     # Required by tests/unit/utils/test_dependency.py but we should take a look a probably removed them
     "datasets > 1.17.0,!= 2.3.2",
     "spacy>=3.5.0,<3.7.0",
+    "pytest-randomly>=3.15.0",
 ]
 
 [tool.pytest.ini_options]