[hotfix][connector/pulsar][docs] Update atEventTime to atPublishTime in JavaDoc

[a49a]

What is the purpose of the change

The atEventTime is deprecated, We need update JavaDoc to atPublishTime

Brief change log

• Update atEventTime to atPublishTime in JavaDoc of PulsarSourceBuilder class

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (no)

[flinkbot]

CI report:

• 0f4846beac1d300f45e2af1aacd43e6059871ebd Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[a49a]

@MartijnVisser Please review it, thanks a lot.

[a49a]

The connector maintainer @syhily says "This is ok". Could we merge it @MartijnVisser ? Thanks a lot.

[MartijnVisser]

The connector maintainer @syhily says "This is ok". Could we merge it @MartijnVisser ? Thanks a lot.

If he approves the PR, yes