Log Message:
time/ruby-timers: update to 4.3.4

4.3.4 (2022-09-02)

* Add clear! function and refactor validate function
* Add tests that use validate function to check heap invariant
* Refactor name of heap validation method from validate! to valid?
* CI against Ruby 3.1
* Modernize gem.
* Migrate to sus for tests.
* Flush queued timers if possible.