Validate foreign key on ServiceHooks
What does this MR do?
In %13.7 we prevented invalid records !47821 (merged) and fixed existing records !48263 (merged).
We can now validate the foreign key. /cc. @Andysoiron
Reference https://docs.gitlab.com/ee/development/database/add_foreign_key_to_existing_column.html.
Edited by Arturo Herrero