chore: No longer push to Docker Hub on release

No longer push to Docker Hub on release as per kedacore/governance#16

Signed-off-by: Tom Kerkhove <kerkhove.tom@gmail.com>

CHANGELOG.md

@@ -47,7 +47,8 @@
 
 ### Breaking Changes
 
-- TODO ([#XXX](https://github.com/kedacore/keda/pull/XXX))
+- No longer push to Docker Hub as of v2.5 as per our [announcement in March 2021](https://github.com/kedacore/keda/discussions/1700).
+  - Learn more about the background on [kedacore/governance#16](https://github.com/kedacore/governance/issues/16)
 
 ### Other