Update CHANGES.md to mention PostgreSQL 10 end of life

Sean Quah · Sean Quah · commit f0dec49f01a7 · 2022-11-08T10:59:36.000Z
diff --git a/CHANGES.md b/CHANGES.md
@@ -6,6 +6,8 @@ They will be removed altogether in Synapse 1.73.0.
 If not already done, server administrators should update their dashboards and alerting rules to avoid using the deprecated metric names.
 See the [upgrade notes](https://matrix-org.github.io/synapse/v1.71/upgrade.html#upgrading-to-v1710) for more details.
 
+**Note:** in line with our [deprecation policy](https://matrix-org.github.io/synapse/latest/deprecation_policy.html) for platform dependencies, this will be the last release to support PostgreSQL 10, which reaches upstream end-of-life on November 10th, 2022. Future releases of Synapse will require PostgreSQL 11+.
+
 No significant changes since 1.71.0rc2.
 
 
