doc: remove cs-format from PR template (rjsf-team#1310)

Author: epicfaace

PULL_REQUEST_TEMPLATE.md

@@ -11,6 +11,5 @@ If this is related to existing tickets, include links to them as well.
 * [ ] **I'm adding or updating code**
  - [ ] I've added and/or updated tests
  - [ ] I've updated [docs](https://react-jsonschema-form.readthedocs.io/) if needed
- - [ ] I've run `npm run cs-format` on my branch to conform my code to [prettier](https://github.com/prettier/prettier) coding style
 * [ ] **I'm adding a new feature**
  - [ ] I've updated the playground with an example use of the feature