Fix Zenodo GitHub link by correcting CITATION.cff metadata

Co-authored-by: geofranzi <15946467+geofranzi@users.noreply.github.com>

Author: Copilot

CITATION.cff

@@ -2,7 +2,7 @@ cff-version: 1.2.0
 message: "If you use BEXIS2 in your research, please cite it using the following metadata."
 title: "BEXIS2"
 version: 4.1.0
-date-released: 15.08.2025
+date-released: 2025-08-15
 authors:
 - family-names: "Zander"
   given-names: "Franziska"
@@ -19,9 +19,8 @@ authors:
 - family-names: "König-Ries"
   given-names: "Birgitta"
   orcid: "https://orcid.org/0000-0002-2382-9722"
-doi: ..
 url: "https://github.com/BEXIS2/Core"
-license: "LGPL-3.0 license"
+license: LGPL-3.0-only
 type: software
 keywords:
   - research data management