fix: Jobs go/sdk event data payload

[tazarov]

Description

Small fix in how JobEvent data is handled - Data now contains the job payload as opposed to the spec (as per original example).

Issue reference

Closes #1095

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• The quickstart code compiles correctly
• You've tested new builds of the quickstart if you changed quickstart code
• You've updated the quickstart's README if necessary
• If you have changed the steps for a quickstart be sure that you have updated the automated validation accordingly. All of our quickstarts have annotations that allow them to be executed automatically as code. For more information see mechanical-markdown. For user guide with examples see Examples.

[tazarov]

Closing as it was fixed with #1097