[SC-13147] Add disk cleanup step to validmind-library CI

[juanmleng]

Pull Request Description

What and why?

This PR adds a disk cleanup step to CI workflows to fix "No space left on device" errors. The cleanup removes unused system packages (Android SDK and .NET runtime) that are pre-installed on GitHub Actions runners but not needed for our Python-based workflows.

How to test

Push this PR and verify that the python.yaml workflow completes successfully without "No space left on device" errors. The cleanup step should run early in the workflow and free up disk space before dependency installation.

What needs special review?

Dependencies, breaking changes, and deployment notes

Release notes

Checklist

• What and why
• Screenshots or videos (Frontend)
• How to test
• What needs special review
• Dependencies, breaking changes, and deployment notes
• Labels applied
• PR linked to Shortcut
• Unit tests added (Backend)
• Tested locally
• Documentation updated (if required)
• Environment variable additions/changes documented (if required)

[github-actions]

PR Summary

This PR introduces a new step in the GitHub Actions CI workflow to free up disk space before continuing with the build. The changes include:

1. Modifications to the GitHub Actions workflow file (.github/workflows/python.yaml) to add a step that runs a disk cleaning script (disk_clean.sh).
2. Addition of a new bash script (disk_clean.sh) that attempts to remove unnecessary directories (specifically an Android library directory and the .NET runtime directory) to free disk space. The script uses sudo privileges to perform directory removals, but it uses a fail-safe (|| true) to avoid script failure if the directories do not exist.

These changes primarily aim to improve CI reliability by ensuring there is sufficient disk space before installing dependencies and running further build steps.

Test Suggestions

• Validate the disk_clean.sh script in a controlled environment to ensure it only removes the intended directories and does not affect other critical system files.
• Run the GitHub Actions workflow in a test repository to verify that the disk cleaning step executes without causing any errors or unintended side effects in subsequent workflow steps.
• Test error scenarios where the directories do not exist to ensure that the script handles these cases gracefully without failing the workflow.