update cxx_status.html

Author: kish1n

clang/www/cxx_status.html

@@ -317,7 +317,7 @@ <h2 id="cxx26">C++2c implementation status</h2>
  <tr>
   <td>Attaching main to the global module</td>
   <td><a href="https://wg21.link/P3618">P3618R0</a> (<a href="#dr">DR</a>)</td>
-  <td class="none" align="center">No</td>
+  <td class="unreleased" align="center">Clang 21</td>
  </tr>
  <tr>
   <td>Expansion Statements</td>