Update citation year and copyright notice in app.py

app.py

@@ -148,10 +148,10 @@ def create_demo():
 
         If you use our toolkit, please cite it:
         ```bibtex
-        @misc{loukas2024grnlptoolkitopensourcenlptoolkit,
+        @misc{loukas-etal2025-greek-nlp-toolkit,
             title={GR-NLP-TOOLKIT: An Open-Source NLP Toolkit for Modern Greek}, 
             author={Lefteris Loukas and Nikolaos Smyrnioudis and Chrysa Dikonomaki and Spyros Barbakos and Anastasios Toumazatos and John Koutsikakis and Manolis Kyriakakis and Mary Georgiou and Stavros Vassos and John Pavlopoulos and Ion Androutsopoulos},
-            year={2024},
+            year={2025},
             eprint={2412.08520},
             archivePrefix={arXiv},
             primaryClass={cs.CL},
@@ -175,7 +175,7 @@ def create_demo():
 
         
 
-        © 2024 The Greek NLP Toolkit. All rights reserved.
+        © 2025 The Greek NLP Toolkit. All rights reserved.
         """
         )