[#957] Update release notes

Signed-off-by: Ziad Mostafa <[email protected]>

Author: zmostafa

doc/release-notes/iceoryx2-unreleased.md

@@ -71,6 +71,8 @@
     [#1133](https://github.com/eclipse-iceoryx/iceoryx2/issues/1133)
 * Enable -Wconversion warning for the C and C++ code
     [#956](https://github.com/eclipse-iceoryx/iceoryx2/issues/956)
+* Add thread sanitizer
+    [#957](https://github.com/eclipse-iceoryx/iceoryx2/issues/957)
 
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