[newlib-cygwin] Cygwin: Add recent fixes to release note 3.6.5

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=9e0162a18d7db74f8692789bf726aa753540fb51

commit 9e0162a18d7db74f8692789bf726aa753540fb51
Author: Takashi Yano <[email protected]>
Date:   Wed Jul 23 20:02:26 2025 +0900

    Cygwin: Add recent fixes to release note 3.6.5

Diff:
---
 winsup/cygwin/release/3.6.5 | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/winsup/cygwin/release/3.6.5 b/winsup/cygwin/release/3.6.5
index 402c8abae..3fbaa0c3a 100644
--- a/winsup/cygwin/release/3.6.5
+++ b/winsup/cygwin/release/3.6.5
@@ -5,3 +5,10 @@ Fixes:
 
 - Fix an ordering problem in sys/termios.h.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-July/258474.html
+
+- Fix doxygen hang due to a deadlock between fclose() and fork().
+  Addresses: https://cygwin.com/pipermail/cygwin-apps/2025-May/044318.html
+  Addresses: https://cygwin.com/pipermail/cygwin/2025-June/258323.html
+
+- Fix multi-thread safety of system().
+  Addresses: https://cygwin.com/pipermail/cygwin/2025-June/258324.html