Remove BuildSnippets opt-out in Microsoft.Azure.WebJobs.Extensions.ServiceBus

[m-redding]

By default, BuildSnippets is set to true in the ci pipelines. In ci.functions.yml in the servicebus directory, BuildSnippets is set to false, explicitly opting out of building snippets. We should probably remove this opt-out to make sure the snippets compile. I think there were some old issues opened about this at one point but they've been closed due to lack of engagement. Opening a new one to track.

Handling the ci.yml in servicebus here #48979

See:

• Update Snippet replacement syntax #20431
• Build snippets during Analyze job by default #33878
• Change default BuildSnippets to check all snippets are used #33877