Duplicate file contents on Create a Materialized View Batch Ingest

There seems to be a copy/paste error where the contents of the datasource definition (`events_per_location_mv.datasource`) match the pipe definition (`events_per_location_mat.pipe`) in [this section](https://github.com/tinybirdco/use-case-examples/tree/main/create_a_materialized_view_batch_ingest#1-create-the-materialized-view).