Remove the pip-install input (#1336)

* Remove the pip-install input

* Resloves merge conflicts

---------

Co-authored-by: gowridurgad <gowridurgad@gmail.com>

docs/advanced-usage.md

@@ -23,7 +23,6 @@
 - [Using `setup-python` on GHES](advanced-usage.md#using-setup-python-on-ghes)
 - [Allow pre-releases](advanced-usage.md#allow-pre-releases)
 - [Using the pip-version input](advanced-usage.md#using-the-pip-version-input)
-- [Using the pip-install input](advanced-usage.md#using-the-pip-install-input)
 
 ## Using the `python-version` input
 
@@ -673,22 +672,3 @@ The version of Pip should be specified in the format `major`, `major.minor`, or
 > The `pip-version` input is supported only with standard Python versions. It is not available when using PyPy or GraalPy.
 
 > Using a specific or outdated version of pip may result in compatibility or security issues and can cause job failures. For best practices and guidance, refer to the official [pip documentation](https://pip.pypa.io/en/stable/).
-
-## Using the pip-install input
-
-The `pip-install` input allows you to install dependencies as part of the Python setup step.
-
-
-```yaml
-      steps:
-      - uses: actions/checkout@v6
-      - name: Set up Python
-        uses: actions/setup-python@v6
-        with:
-          python-version: '3.13'
-          pip-install: -r requirements.txt
-```
-> Note: This feature is intended for standard pip-based dependency installations.
-For complex workflows, or alternative package managers (e.g., poetry, pipenv), we recommend using separate steps to maintain clarity and flexibility.
-
-> The `pip-install` input mirrors the flexibility of a standard pip install command and supports most of its arguments.