Deleted the test `file_donthave_outward_links.adoc`

[rays22]

Deleted the test file_donthave_outward_links.adoc (File nodes terminate experimental design) as it is no longer useful and produces false negative validation tests.

Test plan

I have tested and confirmed that hydrate xls, hydrate ingest and action test functions still work as expected after the fix. I used two different datasets for testing.

Deployment instructions & migrations

• [ ] Need to deploy (pull the update) to the EC2 instance of the ingest-graph-validator tool.