refactor: minor update

[shuiyisong]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

Todo

• bring in https://github.com/GreptimeTeam/pipeline/commit/7d2402701877901871dd1294a65ac937605a6a93
• move PipelineOperator to pipeline crate

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

[shuiyisong]

https://github.com/GreptimeTeam/greptimedb/blob/e2a2e504e83c4f25bf51f8f1a182ff962b0f6eec/src/pipeline/src/mng/pipeline_operator.rs#L90

open_hook is always None?

[paomian]

https://github.com/GreptimeTeam/greptimedb/blob/e2a2e504e83c4f25bf51f8f1a182ff962b0f6eec/src/pipeline/src/mng/pipeline_operator.rs#L90

open_hook is always None?

Yes. There are currently no hooks to execute.