add changelog entry for 5 9 patch 4

Author: DaedalusG

docs/technical-changelog.mdx

@@ -2242,6 +2242,25 @@ The following PRs were merged onto the previous release branch but could not be
 {/* RSS={"version":"v5.10.0", "releasedAt": "2024-11-27"} */}
 
 
+# 5.9 Patch 4
+
+## v5.9.17785
+
+- [sourcegraph](https://github.com/sourcegraph/sourcegraph/releases/tag/v5.9.17785)
+
+- [docker-compose](https://github.com/sourcegraph/deploy-sourcegraph-docker/releases/tag/v5.9.17785)
+
+- [helm](https://github.com/sourcegraph/deploy-sourcegraph-helm/releases/tag/v5.9.17785)
+
+- [kustomize](https://github.com/sourcegraph/deploy-sourcegraph-k8s/releases/tag/v5.9.17785)
+
+### Fix
+
+#### Cody
+
+- Allow specification of additional chat GPT models for Cody `(PR #3434)`
+Backport 5190f43a4d09810e69400c5d0e6d9176b3c4b815 from #3380
+
 # 5.9 Patch 3
 
 ## v5.9.1590