Implementation of py_cc_toolchain rule.
NOTE: This is a beta-quality feature. APIs subject to change until
https://github.com/bazelbuild/rules_python/issues/824 is considered done.
## py_cc_toolchain
py_cc_toolchain(name, headers, python_version)
A toolchain for a Python runtime's C/C++ information (e.g. headers)
This rule carries information about the C/C++ side of a Python runtime, e.g.
headers, shared libraries, etc.
**ATTRIBUTES**
| Name | Description | Type | Mandatory | Default |
| :------------- | :------------- | :------------- | :------------- | :------------- |
| name | A unique name for this target. | Name | required | |
| headers | Target that provides the Python headers. Typically this is a cc_library target. | Label | required | |
| python_version | The Major.minor Python version, e.g. 3.11 | String | required | |