[Flang][WWW] Update Bug Reports link to point to Github issues

Author: kiranchandramohan

flang/docs/_templates/indexsidebar.html

@@ -19,7 +19,7 @@ <h3>Additional Links</h3>
 
 <ul class="want-points">
     <li><a href="https://github.com/llvm/llvm-project/tree/main/flang/">Github Repository</a></li>
-    <li><a href="https://bugs.llvm.org/">Bug Reports</a></li>
+    <li><a href="https://github.com/llvm/llvm-project/issues">Bug Reports</a></li>
     <li><a href="https://reviews.llvm.org/">Code Review</a></li>
     <li><a href="https://flang.llvm.org/doxygen/">Doxygen API</a></li>
 </ul>