z3: add release-notes

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

@@ -350,6 +350,8 @@
 
 - The `mkLayer` and `shellScript` build helpers in `singularity-tools` are deprecated, as they are no longer involved in image-building. Maintainers will remove them in future releases.
 
+- The default version of `z3` has been updated from 4.8 to 4.13. There are still a few packages that need specific 4.8 versions; those will continue to be maintained.
+
 - The `rust.toTargetArch`, `rust.toTargetOs`, `rust.toTargetFamily`, `rust.toTargetVendor`, `rust.toRustTarget`, `rust.toRustTargetSpec`, `rust.toRustTargetSpecShort`, and `rust.IsNoStdTarget` functions are deprecated in favour of the `rust.platform.arch`, `rust.platform.os`, `rust.platform.target-family`, `rust.platform.vendor`, `rust.rustcTarget`, `rust.rustcTargetSpec`, `rust.cargoShortTarget`, `rust.cargoEnvVarTarget`, and `rust.isNoStdTarget` platform attributes respectively.
 
 - All Budgie and `budgiePlugins` packages have been moved to top-level (i.e.,