I'm a newbie and I've just done the "Run your first Delta Live Tables pipeline" tutorial.

The tutorial downloads a publicly available csv baby names file and creates two new Delta Live tables from it.  Now I want to be a good dev and clean up the resources so they aren't cluttering up the environment.  However, I can't find docco for dropping delta live tables.  You can't just drop them separately, because you get an error:

[STREAMING_TABLE_OPERATION_NOT_ALLOWED.DROP_DELTA_LIVE_TABLE] The operation DROP is not allowed: The operation does not apply to Streaming Tables created from Delta Live Tables, instead remove the Streaming Table from the pipeline definition in Delta Live Tables.

I removed the definitions of the two tables from the pipeline definition (per the above error), but then I get the error:

[DLT ERROR CODE: NO_TABLES_IN_PIPELINE] You attempted to update an empty pipeline. This error usually means no tables were discovered in your specified source code. Please verify that your source code includes table definitions.

What is the correct way to remove unwanted Delta Live Tables?