Update ENTSO-E Code List to version 95 and add automated update workflow

[polinaamalinina]

This pull request updates the ENTSO-E Code List reference data from version 91 to version 95.

The update includes the latest official Code List XSD and the required local extension types XSD. The reference data was regenerated from the updated source, including new and updated code lists and concepts introduced in version 95.

The published reference-data files in docs/ were regenerated for the code lists currently included in the publication process.

The request also includes a small fix in Tools/publish.py to correctly preserve github-mark-white.svg and .nojekyll when regenerating the publication directory.

In addition, a new Tools/update_codelist.py workflow has been added to make future Code List updates safer and more repeatable. The updater reads the Code List version and release metadata, validates XSD dependencies, runs the existing Code List generator, verifies the generated RDF metadata, republishes only the configured Code Lists, rebuilds the publication front page, checks protected publication files, and reports expected and unrelated publication changes before stopping for manual review.

The updater does not automatically commit or push changes.

Source version: ENTSO-E Code List v95
Release date in XSD: 2026-06-04

Commits:

• Update ENTSO-E code list to version 95
• Fix preservation of publication files
• Add automated ENTSO-E Code List update workflow
• Fix Code List version comparison error handling

The current pre-update state of master will be preserved separately for future reference and reproducibility.

[polinaamalinina]

Once the master is merged the website https://energy.referencedata.eu/ will be updated accordingly.