Fix/GitHub workflows

[kmilodenisglez]

This pull request makes significant improvements to the project's GitHub Actions workflows and dependency management. The main goals are to modernize, modularize, and secure CI/CD processes by introducing reusable workflow templates, pinning action versions by commit hash for better security, and consolidating dependency update policies. Additionally, the workflows now include clearer copyright and license headers.

Key changes are grouped below:

Workflow Modernization and Modularity

• Replaced the old test.yaml workflow with a new, more flexible test.yml that supports workflow inputs and includes commented templates for integration and Docker image tests. Other workflows (push.yml, pull_request.yml, scheduled.yml, scan.yml, scheduled-scan.yml) now reuse this template for consistency and maintainability. [1] [2] [3] [4] [5] [6]
• Added new scheduled workflows (scheduled.yml, scheduled-scan.yml) to automate regular builds and vulnerability scans, ensuring both released and unreleased code are checked for issues. [1] [2] [3]

Security and Dependency Management

• Updated all GitHub Actions in workflows to be pinned by commit SHA, improving supply chain security and aligning with best practices. [1] [2] [3] [4]
• Introduced a .github/dependabot.yml configuration to automate updates for both GitHub Actions and Python dependencies, with grouping for easier management.

General Improvements and Clean-up

• Added copyright and SPDX license headers to all workflow and configuration files for legal clarity and consistency. [1] [2] [3] [4] [5] [6] [7] [8] [9]
• Removed the obsolete test.yaml workflow file in favor of the new test.yml.

These changes collectively improve maintainability, security, and clarity for CI/CD in the project.