Add issue number to release note

Author: AmrDeveloper

clang/docs/ReleaseNotes.rst

@@ -220,7 +220,7 @@ Improvements to Clang's diagnostics
   :doc:`ThreadSafetyAnalysis` still does not perform alias analysis. The
   feature will be default-enabled with ``-Wthread-safety`` in a future release.
 
-- Improve the diagnostics for chained comparisons to report actual expressions and operators.
+- Improve the diagnostics for chained comparisons to report actual expressions and operators (#GH129069).
 
 - Improve the diagnostics for shadows template parameter to report correct location (#GH129060).