Node.js 20 deprecation and missing python-version warnings

[frack113]

Problem

The action uses outdated dependencies that trigger deprecation warnings:

• actions/checkout@v4 targets Node.js 20 (deprecated)
• actions/setup-python@v5 targets Node.js 20 (deprecated) and does not set python-version

Warnings observed

Node 20 is being deprecated. This workflow is running with Node 24 by default.
[warning]The `python-version` input is not set.  The version of Python currently in `PATH` will be used.
[warning]Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-python@v5.

Proposed fix

Update the composite action to use:

• actions/checkout@v5 (node24)
• actions/setup-python@v6 with python-version: '3.11'

Reproduction

Run any workflow that uses SigmaHQ/sigma-rules-validator@v1 on a recent GitHub Actions runner.