Fix integration test with invalid configuration (#1182)

## Changes

The indentation mistake on the `path` field under `notebook` meant the
pipeline had a single entry with a `nil` notebook field. This was
allowed but incorrect.

While working on the `dyn.Value` approach, this yielded a non-nil but
zeroed `notebook` field and a failure to translate an empty path.

## Tests

Correcting the indentation made the test fail because the file is not a
notebook. I changed it to a `file` reference and the test now passes.

internal/bundle/bundles/deploy_then_remove_resources/template/resources.yml.tmpl

@@ -3,5 +3,5 @@ resources:
     bar:
       name: test-bundle-pipeline-{{.unique_id}}
       libraries:
-        - notebook:
+        - file:
             path: "./foo.py"