Add missing requires for require 'action_dispatch/routing'
Only path requirements are relevant to optimized urls

The bit of URL generation that is optimized is the generation of
the path so things like :host, :port, etc. are irrelevant.
Remove unused method in RouteSet test.
update ruby-oci8 version specification. Closes #15109. [ci skip]

/cc @yahonda
flexible ruby-oci8 version specification. [Gaurav Sharma]

Follow up to #15109.

/cc @Gaurav2728
Merge pull request #15116 from tgxworld/remove_unused_method_in_test

Remove unused method in RouteSet test.
Remove ruby-head from allow_failures matrix
Revert "Remove ruby-head from allow_failures matrix"

This reverts commit 5d2d301024cc0b17f26f6b454ac22a72f1db8a23.