[Bug] tidb-cdc read snapshort need to more memory

[caohb1985]

Search before asking

• [X] I searched in the issues and found nothing similar.

Flink version

1.17.1

Flink CDC version

3.0.0

Database and its version

7.2.2

Minimal reproduce step

reduce take up memory

What did you expect to see?

reduce take up memory

What did you see instead?

reduce take up memory

Anything else?

reduce take up memory

Are you willing to submit a PR?

• [X] I'm willing to submit a PR!