Snippets factory: prevent usage of `snippets` factory
What does this MR do and why?
Contributes to #494689 (closed)
Second part of Use a specific snippet factory in tests (!167284 - merged).
Problem
snippets
factory generates invalid records, project_snippet
or
personal_snippet
should be used instead.
Solution
Prevent creation of snippets
factory
Edited by Vasilii Iakliushin