Remove record-tests step from contribution guides (#10223)

contributing/how-to-contribute.md

@@ -83,8 +83,7 @@ The core team is monitoring for pull requests. We will review your pull request
 5. Format your code with [prettier](https://github.com/prettier/prettier) (`npm run prettier`).
 6. Make sure your code lints (`npm run lint`).
 7. Run the [Flow](https://flowtype.org/) typechecks (`npm run flow`).
-8. If you added or removed any tests, run `./scripts/fiber/record-tests` before submitting the pull request, and commit the resulting changes. You can see the full output of fiber tests with `REACT_DOM_JEST_USE_FIBER=1 npm test`.
-9. If you haven't already, complete the CLA.
+8. If you haven't already, complete the CLA.
 
 ### Contributor License Agreement (CLA)