Release v2.5.3

[kmilodenisglez]

This pull request modernizes and simplifies the example chaincode projects, improves release workflow robustness, and enhances documentation for users and contributors. The most important changes are as follows:

Example Code Modernization and Simplification:

• All example chaincode projects now import fabric_chaincode_python directly as an installed package, removing custom sys.path logic and ensuring consistency for both local development and standalone use. Requirements files are updated to depend on fabric-chaincode-python instead of specifying individual dependencies. [1] [2] [3] [4] [5] [6]
• Example documentation and READMEs are updated to reference the new import paths and recommend using a virtual environment (.venv) and the installed package for running examples. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]

Release Workflow Improvements:

• The release workflow (.github/workflows/release.yml) now includes a step to verify that the git tag matches the package version in the built wheel, preventing accidental mismatches. It also adds a metadata check using twine.

Security and Compliance Enhancements:

• Adds an OpenSSF Scorecard GitHub Action workflow (.github/workflows/ossf-scorecard.yml) to regularly scan the repository for security best practices and upload results to code scanning.
• The OpenSSF Scorecard badge in the README.md is updated to reference the GitHub Actions workflow for more accurate status reporting.

Documentation and Roadmap Updates:

• Updates the roadmap to mark PyPI publishing and migration to the official project as complete.
• Minor documentation fixes and clarifications, including correct import examples for package testing and improved references to documentation.

These changes improve the developer experience, ensure package correctness, and enhance the security posture of the project.