Add python-kafka integration test

[rukai]

This PR introduces kafka integration tests using the kafka-python-ng driver, following a similar approach as #1690

This includes:

• a uv python project which runs runs a simple smoke test against a kafka cluster.
• a rust helper ensure_uv_is_installed to install uv to shotover's target directory
• a rust helper run_python_smoke_test that calls ensure_uv_is_installed and then runs the uv project, passing in required configuration.
• an integration test which calls run_python_smoke_test

uv was chosen as it drastically simplifies python package management and is easy to install.
Compare the current implementation to https://github.com/shotover/shotover-proxy/pull/1267/files where we had to manually wrangle venvs in order to create an isolated and reproducible python environment. uv handles all of that for us and is a lot faster.

Time to run

• First run of the test completes in 14s due to installing uv
• On reruns the test completes in 6s

Future work

This sets us up to write an integration test for the python driver that uses sasl scram which is known to be broken in shotover.
However I've left that out of this initial PR to keep scope down.

[codspeed-hq]

CodSpeed Performance Report

Merging #1782 will not alter performance

_{Comparing rukai:kafka_python_test (51f91ad) with main (61b5a98)}

Summary

✅ 38 untouched benchmarks