✨ Add support for installing extras to `python-environment` action

[Nicoretti]

Summary

Currently, the python-environment GitHub action installs the project without any extras. This issue proposes adding a parameter to the action that enables the installation of specific extras.

Details

Background & Context

Often times, a Python project has optional dependencies that are not required for basic functionality but are necessary for certain features to work. These optional dependencies are often installed as extras. Currently, the python-environment action does not have an option to specify these extras during installation.

Proposed Solution

The proposed solution is to add an optional parameter to the python-environment action that enables the installation of extras. Users can specify the extras they need at runtime, and the action will install the project along with those extras.

Example Usage

Here's an example of how the new parameter can be used in a workflow:

- name: Install Project with Extras
  uses: .../python-environment
  with:
    version: 3.8
    extras: some_extra, another_extra

In the above example, the python-environment action installs Python 3.8 and the project, along with the some_extra and another_extra extras.

Task(s)

• [ ] Add the new extras parameter to the python-environment action.
• [ ] Update action documentation to include the new parameter and usage examples.