Revert "Integration tests support the OPTIONS http method"

This reverts commit ad46884af567d6f8d6d8d777f372c39e81a560ba.

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/lib/action_dispatch/testing/integration.rb
	actionpack/test/controller/integration_test.rb

Reason: It will conflict with a lot of test cases. Better to call
`process` directly since this is a very uncommon HTTP method.

Fixes #10638.