[Good First Issue] Write Unit Tests for `TrafficRegulator`

[Chillax-0v0]

Problem Description

The com.automq.stream.s3.operator.TrafficRegulator class currently lacks comprehensive unit tests.

Required Changes

1. Read and understand the original implementation (calculates the next throttling value based on historical input sequences, specifically using an algorithm similar to TCP congestion control algorithms)
2. Validate that the regulate method works as expected by mocking classes like TrafficMonitor and TrafficRateLimiter

[aiivar]

/assign

[DovahkiinGA]

/assign