docs/release-notes: update changelog for v5.0.5 release

bot:notacherrypick

Signed-off-by: Wenduo Wang <wenduwan@amazon.com>

docs/release-notes/changelog/v5.0.x.rst

@@ -4,6 +4,25 @@ Open MPI v5.0.x series
 This file contains all the NEWS updates for the Open MPI v5.0.x
 series, in reverse chronological order.
 
+Open MPI version v5.0.5
+--------------------------
+:Date: 23 July 2024
+
+  .. note:: This is a quick follow-up release that fixes v5.0.4 which does
+            not compile on macOS(arm64) with out-of-box Apple clang compiler;
+            v5.0.4 and v5.0.5 do NOT have functional differences otherwise.
+
+- Internal PMIx and PRRTe versions:
+
+  - PMIx (v5.0.3). Commit hash: ``8ab6d680b90afd6e61766220a8724065a1b554a7``.
+  - PRRTE (v3.0.6). Commit hash: ``b68a0acb32cfc0d3c19249e5514820555bcf438b``.
+
+- Bugfixes and changes
+
+  - Fix a macro typo that breaks macOS build with Apple clang on arm64 platforms
+
+- Many thanks to Lisandro Dalcin for reporting the bug
+
 Open MPI version v5.0.4
 --------------------------
 :Date: 19 July 2024