You have mismatched version of airbyte-cdk and base image. In the new version of airbyte-cdk, the manifest_declarative_source.py has moved to "legacy" folder. Your base image is still importing the old path(No legacy folder exists).

You can do:

Downgrade CDK to match base image : airbyte-cdk = "6.59.0"

or

you can upgrade the latest base image 4.0+ (if its exists)