Release 0.6.28

Refactor Throttle operator to avoid while loops (#173)

## Description

In consumer usage of the throttle operator, we observed hangs in UI tests that only occurred when the `throttle` operator was used.

This seems to be related to the `while` loop that was used to await next elements. If the upstream was not emitting more elements, it seems the `while` loop caused issues with app execution.

To Do:
- [x] Run ThrottleSequenceTests x1000 locally