Hi all Background: When the schemas of a topic are lost, all of the messages in the topic can not be consumed successfully, and producers can not publish messages anymore. This mechanism alerts users to try to recover their schemas or recreate their topics.
https://github.com/apache/pulsar/pull/23395 added a patch: producers will rebuild schemas if the original schemas were lost, which will mix the old schema and new schema as the same schema ID. For example: - send M1 with schema `Int32`, get schema id: `1` - send M2 with schema `String`, get schema id: `2` - schemas are lost - send M3 with schema `String`, get schema id `1` The messages `M1` and `M3` use different schemas, but have the same schema id, but users assume all things are fine, which is dangerous. So I want to revert this PR. Thanks Yubiao Feng
