build(deps): bump tower-test from 35188ec to 251296d

Bumps [tower-test](https://github.com/tower-rs/tower) from `35188ec` to `251296d`.
- [Release notes](https://github.com/tower-rs/tower/releases)
- [Commits](tower-rs/tower@35188ec...251296d)

---
updated-dependencies:
- dependency-name: tower-test
  dependency-version: 251296dc54a044383dffd16d2179b443e2615672
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]