Update to using uv

Co-authored-by: Joe Banks <joe@jb3.dev>

Author: janine9vn

pydis_site/templates/events/pages/code-jams/12/rules.html

@@ -21,7 +21,7 @@
     <li>
         <p>
             You must document precisely how to install and run your project.
-            This should be as easy as possible, which means you should consider using dependency managers like <code>pipenv</code> or <code>poetry</code>.
+            This should be as easy as possible, which means you should consider using dependency managers like <code>uv</code> or <code>poetry</code>.
             We would also encourage you to use <code>docker</code> and <code>docker-compose</code> to containerize your project, but this isn't a requirement.
         </p>
     </li>