Cygwin: Document recent fixes in release note

Author: tyan0

winsup/cygwin/release/3.6.2

@@ -16,3 +16,9 @@ Fixes:
 
 - Fix cygwin_conv_path writing to 'to' pointer before size is checked.
   Addresses: https://cygwin.com/pipermail/cygwin/2025-April/258068.html
+
+- Fix handle leak occured when the signal handler calls longjmp().
+  https://sourceware.org/pipermail/cygwin/2025-March/257726.html
+
+- Fix conserver-config error.
+  https://cygwin.com/pipermail/cygwin/2025-April/258086.html