fix(metrics): correct channel name (#2623)

<!--
Please read and fill out this form before submitting your PR.

Please make sure you have reviewed our contributors guide before
submitting your
first PR.

NOTE: PR titles should follow semantic commits:
https://www.conventionalcommits.org/en/v1.0.0/
-->

## Overview

Fix metrics channel.

<!-- 
Please provide an explanation of the PR, including the appropriate
context,
background, goal, and rationale. If there is an issue with this
information,
please provide a tl;dr and link the issue. 

Ex: Closes #<issue number>
-->

Author: julienrbrt

block/metrics.go

@@ -124,7 +124,7 @@ func PrometheusMetrics(namespace string, labelsAndValues ...string) *Metrics {
 	}, labels).With(labelsAndValues...)
 
 	// Initialize channel buffer usage gauges
-	channelNames := []string{"header_in", "data_in", "header_store", "data_store", "retrieve", "da_includer", "tx_notify"}
+	channelNames := []string{"height_in", "header_store", "data_store", "retrieve", "da_includer", "tx_notify"}
 	for _, name := range channelNames {
 		m.ChannelBufferUsage[name] = prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
 			Namespace: namespace,

block/metrics_test.go

@@ -18,9 +18,8 @@ func TestMetrics(t *testing.T) {
 		assert.NotNil(t, em.NumTxs)
 
 		// Test channel metrics initialization
-		assert.Len(t, em.ChannelBufferUsage, 7)
-		assert.NotNil(t, em.ChannelBufferUsage["header_in"])
-		assert.NotNil(t, em.ChannelBufferUsage["data_in"])
+		assert.Len(t, em.ChannelBufferUsage, 6)
+		assert.NotNil(t, em.ChannelBufferUsage["height_in"])
 		assert.NotNil(t, em.DroppedSignals)
 
 		// Test error metrics initialization
@@ -75,6 +74,7 @@ func TestMetrics(t *testing.T) {
 
 		// Test maps are initialized
 		assert.Len(t, em.ChannelBufferUsage, 6)
+		assert.NotNil(t, em.ChannelBufferUsage["height_in"])
 		assert.Len(t, em.ErrorsByType, 5)
 		assert.Len(t, em.OperationDuration, 5)
 		assert.Len(t, em.StateTransitions, 3)
@@ -176,8 +176,7 @@ func TestMetricsIntegration(t *testing.T) {
 	em.GoroutineCount.Set(50)
 
 	// Test channel metrics
-	em.ChannelBufferUsage["header_in"].Set(5)
-	em.ChannelBufferUsage["data_in"].Set(3)
+	em.ChannelBufferUsage["height_in"].Set(5)
 
 	// Test error metrics
 	em.ErrorsByType["block_production"].Add(1)