Plugins: Add metric to track plugin backend target (#95976)

* add metric to track plugin backend target

* tidy

* fix test

pkg/services/pluginsintegration/pipeline/pipeline.go

@@ -73,6 +73,7 @@ func ProvideInitializationStage(cfg *config.PluginManagementCfg, pr registry.Ser
 			RegisterPluginRolesStep(roleRegistry),
 			RegisterActionSetsStep(actionSetRegistry),
 			ReportBuildMetrics,
+			ReportTargetMetrics,
 			initialization.PluginRegistrationStep(pr),
 		},
 	})

pkg/services/pluginsintegration/pipeline/steps.go

@@ -127,6 +127,16 @@ func ReportBuildMetrics(_ context.Context, p *plugins.Plugin) (*plugins.Plugin,
 	if !p.IsCorePlugin() && !p.IsBundledPlugin() {
 		metrics.SetPluginBuildInformation(p.ID, string(p.Type), p.Info.Version, string(p.Signature))
 	}
+
+	return p, nil
+}
+
+// ReportTargetMetrics reports target information for all backend plugins.
+func ReportTargetMetrics(_ context.Context, p *plugins.Plugin) (*plugins.Plugin, error) {
+	if p.Backend {
+		metrics.SetPluginTargetInformation(p.ID, string(p.Target()))
+	}
+
 	return p, nil
 }