Remove mentions to outdated and unused pkg_resources

Fix gh-2391.

Signed-off-by: Juan Luis Cano Rodríguez <[email protected]>

docs/source/extend_kedro/plugins.md

@@ -4,7 +4,7 @@ Kedro plugins allow you to create new features for Kedro and inject additional c
 
 ## Overview
 
-Kedro uses [`setuptools`](https://setuptools.readthedocs.io/en/latest/setuptools.html), which is a collection of enhancements to the Python `distutils` to allow developers to build and distribute Python packages. Kedro uses various entry points in [`pkg_resources`](https://setuptools.readthedocs.io/en/latest/setuptools.html) to provide plugin functionality.
+Kedro extension mechanism is built on [pluggy](https://pluggy.readthedocs.io/), a solid plugin management library that was created for the [pytest](https://docs.pytest.org/) ecosystem. pluggy relies on [entry points](https://packaging.python.org/en/latest/specifications/entry-points/), a Python mechanism for packages to provide components that can be discovered by other packages using [`importlib.metadata`](https://docs.python.org/3/library/importlib.metadata.html#entry-points).
 
 ## Example of a simple plugin
 
@@ -189,7 +189,7 @@ When you are ready to submit your code:
 2. Choose a command approach: `global` and / or `project` commands:
    - All `global` commands should be provided as a single `click` group
    - All `project` commands should be provided as another `click` group
-   - The `click` groups are declared through the [`pkg_resources` entry_point system](https://setuptools.readthedocs.io/en/latest/setuptools.html)
+   - The `click` groups are declared through the [entry points mechanism](https://setuptools.pypa.io/en/latest/userguide/entry_point.html)
 3. Include a `README.md` describing your plugin's functionality and all dependencies that should be included
 4. Use GitHub tagging to tag your plugin as a `kedro-plugin` so that we can find it