Support dependencies with circular dependencies

[brandonchinn178]

This is a bit of an odd edge case, so not sure if anything can be done, but apparently pip and uv both allow dependencies with circular dependencies, e.g. the streamlit-extras library depends on streamlit-faker, which depends on streamlit-extras.

Currently, pycross fails:

ERROR: /private/var/tmp/_bazel_bchinn/...: in pycross_wheel_library rule @@...//_lock:streamlit-extras@0.6.0: cycle in dependency graph:
    @@pypi//:streamlit-extras (82690b67388e26be5f5e7a7bc0f470ce7530d12a73e138cc7419ca8835a87c31)
.-> @@pypi//_lock:streamlit-extras@0.6.0 (82690b67388e26be5f5e7a7bc0f470ce7530d12a73e138cc7419ca8835a87c31)
|   @@pypi//_lock:streamlit-faker@0.0.3 (82690b67388e26be5f5e7a7bc0f470ce7530d12a73e138cc7419ca8835a87c31)
`-- @@pypi//_lock:streamlit-extras@0.6.0 (82690b67388e26be5f5e7a7bc0f470ce7530d12a73e138cc7419ca8835a87c31)

[jvolkman]

We should be able to implement cycle detection and make all involved libraries resolve to essentially a group of interdependent libraries.

I was working on that at some point, but I had first started adding first class support for extras (with the pkg[opt] notation) which will expand the dependency model.