Update docs/changelog/119227.yaml

Author: PeteGillinElastic

docs/changelog/119227.yaml

@@ -0,0 +1,12 @@
+pr: 119227
+summary: Remove unfreeze REST endpoint
+area: Indices APIs
+type: breaking
+issues: []
+breaking:
+  title: Remove unfreeze REST endpoint
+  area: Indices APIs
+  details: Please describe the details of this change for the release notes. You can
+    use asciidoc.
+  impact: Please describe the impact of this change to users
+  notable: false