doc: 24.11: document isync version bump

Author: felipeqq2

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -465,6 +465,8 @@
 - Minimal installer ISOs are no longer built on the small channel.
   Please obtain installer images from the full release channels.
 
+- The `isync` package has been updated to version `1.5.0`, which introduces some breaking changes. See the [compatibility concerns](https://sourceforge.net/projects/isync/files/isync/1.5.0/) for more details.
+
 ## Other Notable Changes {#sec-release-24.11-notable-changes}
 
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