fixup tracing

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

event.go

@@ -1,12 +1,14 @@
 package kgo
 
 import (
+	"context"
 	"sync"
 
 	"go.unistack.org/micro/v3/broker"
 )
 
 type event struct {
+	ctx   context.Context
 	topic string
 	err   error
 	sync.RWMutex
@@ -14,6 +16,10 @@ type event struct {
 	ack bool
 }
 
+func (p *event) Context() context.Context {
+	return p.ctx
+}
+
 func (p *event) Topic() string {
 	return p.topic
 }