fix(broadcast): correct stale model name in newsletter copy

Claude Fable 5 was added in #4921 but removed in #5020, so it is no longer in
the model catalog. Replace it with Claude Opus 4.8 (current flagship in
providers/models.ts) so the newsletter doesn't advertise an unavailable model.

Author: waleedlatif1

apps/sim/emails/broadcasts/july-1.html

@@ -364,7 +364,7 @@ <h2 style="margin:0;color:#1A1A1A;font-family:'Season Sans',-apple-system,'SF Pr
 
           <tr>
             <td align="left" class="mobile-pad" style="color:#525252;font-family:'Season Sans',-apple-system,'SF Pro Display','SF Pro Text','Helvetica',sans-serif;font-size:14px;font-weight:430;line-height:22px;word-break:break-word;padding-bottom:30px;text-align:left;text-wrap:pretty;">
-              <p style="margin:0;">Sim got a redesign - the whole workspace, docs, and site now share one cleaner, lighter design system. We added Claude Fable 5, DeepSeek V4, and Mistral Medium 3.5, along with providers like Sakana, Together AI, Baseten, and Ollama Cloud, with multi-key rotation. And we connected Sim to dozens more tools - Square, Brex, Vanta, Temporal, ClickHouse, Attio, and many more.</p>
+              <p style="margin:0;">Sim got a redesign - the whole workspace, docs, and site now share one cleaner, lighter design system. We added Claude Opus 4.8, DeepSeek V4, and Mistral Medium 3.5, along with providers like Sakana, Together AI, Baseten, and Ollama Cloud, with multi-key rotation. And we connected Sim to dozens more tools - Square, Brex, Vanta, Temporal, ClickHouse, Attio, and many more.</p>
             </td>
           </tr>