Flakes due to missing python packages

[UebelAndre]

https://buildkite.com/bazel/rules-rust-rustlang/builds/12763#019369d0-adaf-48ab-aca7-067df6313621
I've noticed this on a few jobs recently

$ curl -sS https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/bazelci.py?1732647102 -o bazelci.py
python3 bazelci.py runner --task=crate_universe_examples_macos
Traceback (most recent call last):
  File "/Users/buildkite/builds/bk-macos-arm64-0n05/bazel/rules-rust-rustlang/bazelci.py", line 34, in <module>
    import requests
ModuleNotFoundError: No module named 'requests'
🚨 Error: The command exited with status 1
^^^ +++
user command error: exit status 1