Udpate copyright year in documentation.

Author: blapie

README.md

@@ -228,7 +228,7 @@ The software is distributed under the Boost Software License, Version 1.0.
 See accompanying file [LICENSE.txt](./LICENSE.txt) or copy at [http://www.boost.org/LICENSE_1_0.txt][license_url].
 Contributions to this project are accepted under the same license.
 
-Copyright &copy; 2010-2024 SLEEF Project, Naoki Shibata and contributors.<br/>
+Copyright &copy; 2010-2025 SLEEF Project, Naoki Shibata and contributors.<br/>
 
 
 <!-- Repository links -->

docs/_config.yml

@@ -4,7 +4,7 @@ logo: img/sleef-logo-notext.svg
 favicon_ico: "/img/favicon.ico"
 
 theme: just-the-docs
-footer_content: "Copyright &copy; 2010-2024 SLEEF Project, Naoki Shibata and contributors. <a href=\"https://github.com/shibatch/sleef/blob/master/LICENSE.txt\">SLEEF is open-source software and is distributed under the Boost Software License, Version 1.0.</a>"
+footer_content: "Copyright &copy; 2010-2025 SLEEF Project, Naoki Shibata and contributors. <a href=\"https://github.com/shibatch/sleef/blob/master/LICENSE.txt\">SLEEF is open-source software and is distributed under the Boost Software License, Version 1.0.</a>"
 
 aux_links:
   "SLEEF On GitHub": https://github.com/shibatch/sleef