replace retired python-dev mailing list link with Python Discourse

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: JacobCoffee

src/components/Footer.astro

@@ -24,7 +24,7 @@ const year = new Date().getFullYear();
         <h3 class="text-xs font-semibold uppercase tracking-widest text-zinc-500 dark:text-zinc-400">Related Links</h3>
         <ul class="mt-3 space-y-2">
           <li><a href="https://www.python.org" class="text-sm text-zinc-600 transition-colors hover:text-[#306998] dark:text-zinc-300 dark:hover:text-[#ffd43b]">python.org</a></li>
-          <li><a href="https://mail.python.org/mailman3/lists/python-dev.python.org/" class="text-sm text-zinc-600 transition-colors hover:text-[#306998] dark:text-zinc-300 dark:hover:text-[#ffd43b]">Python-Dev Mailing List</a></li>
+          <li><a href="https://discuss.python.org" class="text-sm text-zinc-600 transition-colors hover:text-[#306998] dark:text-zinc-300 dark:hover:text-[#ffd43b]">Python Discourse</a></li>
           <li><a href="https://devguide.python.org" class="text-sm text-zinc-600 transition-colors hover:text-[#306998] dark:text-zinc-300 dark:hover:text-[#ffd43b]">Python Developer's Guide</a></li>
         </ul>
       </div>