chore(dpp)!: do not allow dependentSchemas

[shumkov]

Issue being fixed or feature implemented

dependentSchemas could lead to validation errors and misparsing of document type. We don't support conditions in JSON Schema atm

What was done?

• Removed dependentSchemas from document meta schema

How Has This Been Tested?

None

Breaking Changes

Previous contracts might become invalid.

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have added "!" to the title and described breaking changes in the corresponding section if my code contains any
• I have made corresponding changes to the documentation if needed

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone