Third-party transitive dependencies seem to be packaged into wheels incorrectly

# 🐞 bug report

### Affected Rule

py_wheel

### Is this a regression?

Doubtful

### Description

When building a wheel using `py_wheel`, third-party pip requirements are being installed into an incorrect directory, preventing them from being properly installed/used in Python environments.

## 🔬 Minimal Reproduction

```
load("@rules_python//python:defs.bzl", "py_binary", "py_library")
load("@rules_python//python:packaging.bzl", "py_package", "py_wheel")
load("@python_deps//:requirements.bzl", "requirement")

filegroup(
name = "srcs",
srcs = glob(
[
"**/*.py",
"*.py",
],
exclude = ["tests/**"],
),
)

py_deps = [
requirement("behave"),
]

py_library(
name = "regression_harness",
srcs = [":srcs"],
visibility = ["//bt:__subpackages__"],
deps = py_deps,
)

py_package(
name = "regression_harness_pkg",
deps = [
":regression_harness",
],
)

py_wheel(
name = "regression_harness_wheel",
distribution = "regression_harness",
version = "1.0.0",
deps = [
":regression_harness_pkg",
],
)
```

## 🔥 Exception or Error

The wheel builds as usual, and looks (at least mostly) correct. However, upon installing the wheel, we see the following:

gitpod /workspace/tribe $ ls /tmp/test/lib/python3.8/site-packages/

bin                       pip-24.1.2.virtualenv                  site-packages

bt                        pkg_resources                          _virtualenv.pth

_distutils_hack           __pycache__                            _virtualenv.py

distutils-precedence.pth  regression_harness-0.0.8940.dist-info  wheel

include                   setuptools                             wheel-0.43.0.dist-info

lib                       setuptools-57.4.0.dist-info            wheel-0.43.0.virtualenv

pip                       setuptools-57.4.0.virtualenv

pip-24.1.2.dist-info      share

`regression_harness` was in fact installed, and is available, but the third-party transitive dependencies are within a **nested** site-packages directory _within_ the site-packages.

gitpod /workspace/tribe $ ls /tmp/test/lib/python3.8/site-packages/site-packages/

behave                  parse-1.20.2.dist-info  parse_type-0.6.2.dist-info  six-1.16.0.dist-info

behave-1.2.6.dist-info  parse.py                __pycache__                 six.py

__init__.py             parse_type              setuptools_behave.py

Of course, this means that they're not available within the environment, as that directory is not part of the PYTHONPATH.

I have tried stripping the `site-packages` prefix when building the wheel, but this makes the wheel file invalid as it will contain multiple `.dist-info` files.

Am I doing something incorrectly? This seems like a bug to me, but I can't imagine that others wouldn't have seen this.

## 🌍 Your Environment

**Operating System:**

  

Ubuntu Focal

  

**Output of `bazel version`:**

  

gitpod /workspace/tribe $ bazel version

Bazelisk version: v1.17.0

Build label: 6.2.1

Build target: bazel-out/k8-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar

Build time: Fri Jun 2 16:59:58 2023 (1685725198)

Build timestamp: 1685725198

Build timestamp as int: 1685725198

  

**Rules_python version:**

  

0.27.1

e85ae30de33625a63eca7fc40a94fea845e641888e52f32b6beea91e8b1b2793

  

**Anything else relevant?**

Bắt đầu với bản tái hiện py_package và py_wheel được cung cấp, đồng thời kiểm tra các đường dẫn và nội dung đã cài đặt của wheel được tạo. So sánh vị trí của các phần phụ thuộc bắc cầu như behave với bố cục cấp cao nhất dự kiến của wheel; issue được hoàn tất khi các phần phụ thuộc đó được cài đặt trực tiếp vào site-packages của môi trường và vẫn là nội dung wheel hợp lệ.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.