Instrument tracing across dashboards (#91937)

Add tracing across dashboards and accesscontrol

pkg/api/api.go

@@ -46,8 +46,11 @@ import (
 	publicdashboardsapi "github.com/grafana/grafana/pkg/services/publicdashboards/api"
 	"github.com/grafana/grafana/pkg/services/serviceaccounts"
 	"github.com/grafana/grafana/pkg/services/user"
+	"go.opentelemetry.io/otel"
 )
 
+var tracer = otel.Tracer("github.com/grafana/grafana/pkg/api")
+
 // registerRoutes registers all API HTTP routes.
 func (hs *HTTPServer) registerRoutes() {
 	reqNoAuth := middleware.NoAuth()