Fix config used in Otel manager test (#6966)

Otel collector exposes metrics on port 8888 by default, which can cause
conflicts with other applications in tests. Disable this.

Use the nopexporter and debugpreceiver in the test instead of the
otlpexporter and otlpreceiver. This is faster and doesn't require
binding to any ports as well.

internal/pkg/otel/manager/manager_test.go

@@ -24,38 +24,36 @@ import (
 var (
 	testConfig = map[string]interface{}{
 		"receivers": map[string]interface{}{
-			"otlp": map[string]interface{}{
-				"protocols": map[string]interface{}{
-					"grpc": map[string]interface{}{
-						"endpoint": "0.0.0.0:4317",
-					},
-				},
-			},
+			"nop": map[string]interface{}{},
 		},
 		"processors": map[string]interface{}{
 			"batch": map[string]interface{}{},
 		},
 		"exporters": map[string]interface{}{
-			"otlp": map[string]interface{}{
-				"endpoint": "otelcol:4317",
-			},
+			"debug": map[string]interface{}{},
 		},
 		"service": map[string]interface{}{
+			"telemetry": map[string]interface{}{
+				"metrics": map[string]interface{}{
+					"level":   "none",
+					"readers": []any{},
+				},
+			},
 			"pipelines": map[string]interface{}{
 				"traces": map[string]interface{}{
-					"receivers":  []string{"otlp"},
+					"receivers":  []string{"nop"},
 					"processors": []string{"batch"},
-					"exporters":  []string{"otlp"},
+					"exporters":  []string{"debug"},
 				},
 				"metrics": map[string]interface{}{
-					"receivers":  []string{"otlp"},
+					"receivers":  []string{"nop"},
 					"processors": []string{"batch"},
-					"exporters":  []string{"otlp"},
+					"exporters":  []string{"debug"},
 				},
 				"logs": map[string]interface{}{
-					"receivers":  []string{"otlp"},
+					"receivers":  []string{"nop"},
 					"processors": []string{"batch"},
-					"exporters":  []string{"otlp"},
+					"exporters":  []string{"debug"},
 				},
 			},
 		},
@@ -191,7 +189,7 @@ func TestOTelManager_ConfigError(t *testing.T) {
 
 	go func() {
 		err := m.Run(ctx)
-		require.ErrorIs(t, err, context.Canceled, "otel manager should be cancelled")
+		assert.ErrorIs(t, err, context.Canceled, "otel manager should be cancelled")
 	}()
 
 	// watch is synchronous, so we need to read from it to avoid blocking the manager