docs: update CHANGELOG.md for v3.6.0 (#13904)

Signed-off-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Signed-off-by: Alan Clucas <alan@clucas.org>
Co-authored-by: Joibel <1827156+Joibel@users.noreply.github.com>
Co-authored-by: Alan Clucas <alan@clucas.org>

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## v3.6.0 (2024-10-31)
+
+Full Changelog: [v3.6.0-rc4...v3.6.0](https://github.com/argoproj/argo-workflows/compare/v3.6.0-rc4...v3.6.0)
+
+### Selected Changes
+
+<details><summary><h3>Contributors</h3></summary>
+
+</details>
+
 ## v3.6.0-rc4 (2024-10-31)
 
 Full Changelog: [v3.6.0-rc3...v3.6.0-rc4](https://github.com/argoproj/argo-workflows/compare/v3.6.0-rc3...v3.6.0-rc4)