fix: Improve test reliability

[Tranquility2]

This was originally only to fix #983 but I took the time to fix some other stuff that made reading and running the tests less optimal.

• Fix test_ryuk flakiness: replace fixed sleep with polling helper (_wait_for_container_removed) that waits for Ryuk to finish reaping
• Suppress expected error logs in test_compose_volumes and test_wait_strategies to reduce test noise
• Add test = False to TestcontainersConfiguration to prevent pytest from trying to collect it as a test class
• Add long_running pytest marker to pyproject.toml
• Mark DinD/DooD tests as long_running since they build Docker images and take x4 than all the other tests combined
• Add quick-core-tests Makefile target to run core tests excluding long_running tests for faster feedback loops

[Tranquility2]

Looks like there is an issue with cassandra-driver (v3.29.3) in python 3.14
This blocks:

1. linting
2. test with python 3.14

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.96%. Comparing base (44dd40b) to head (b9ac363).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #984      +/-   ##
==========================================
+ Coverage   78.94%   78.96%   +0.01%     
==========================================
  Files          14       14              
  Lines        1216     1217       +1     
  Branches      142      142              
==========================================
+ Hits          960      961       +1     
  Misses        214      214              
  Partials       42       42              

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[Tranquility2]

@alexanderankin mind taking a look?