[FLINK-32024][docs] Short code related to externalized connector retrieve version from its own data yaml

[reswqa]

Purpose of the change

As Title

Brief change log

• Remove the version parameter from shortcode.
• Add version info to pulsar.yml.

Verifying this change

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

Significant changes

(Please check any boxes [x] if the answer is "yes". You can first publish the PR and check them afterwards, for
convenience.)

• Dependencies have been added or upgraded
• Public API has been changed (Public API is any class annotated with @Public(Evolving))
• Serializers have been changed
• New feature has been introduced
  • If yes, how is this documented? (not applicable / docs / JavaDocs / not documented)