[improve][broker] PIP-406: Introduce metrics related to dispatch_throttled_count #23126

Job	Run time
Preconditions	10s
Build and License check	0s
Build Pulsar docker image	0s
Build Pulsar java-test-image docker image	0s
CI - Unit - ${{ matrix.name }}	0s
CI - System - ${{ matrix.name }}	0s
CI Flaky - System - ${{ matrix.name }}	0s
CI - Integration - ${{ matrix.name }}	0s
CI - Unit - Upload Coverage	0s
Run CodeQL Analysis	0s
CI - System - Upload Coverage	0s
CI - Integration - Upload Coverage	0s
OWASP dependency check	0s
Build Pulsar on MacOS	0s
Delete system test docker image artifact	0s
Pulsar CI checks completed	11s
Delete integration test docker image artifact	0s
	21s

Provide feedback