[docs] Update copyright year to 2025 in the website footer. (iree-org#19599)

See prior updates: iree-org#16028

> Happy New Year 🎉
> 
> Yes, this is a bit silly. We still like to intentionally update the
copyright year in this one location so the website appears fresh.

Author: ScottTodd

docs/website/mkdocs.yml

@@ -83,7 +83,7 @@ exclude_docs: |
   **/snippets/*.md
 
 copyright: |
-  Copyright © 2024 IREE a Series of LF Projects, LLC.
+  Copyright © 2025 IREE a Series of LF Projects, LLC.
   For web site terms of use, trademark policy and other project policies please
   see <a href="https://lfprojects.org">https://lfprojects.org</a>.