Removed unused use statements.
minor #9304 Dead code v2.2 (hhamon)

This PR was merged into the 2.2 branch.

Discussion
----------

Dead code v2.2

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | ~
| License       | MIT
| Doc PR        | ~

Commits
-------

0946be6 Removed unused use statements.