replace ioutil in testing of gchat

Signed-off-by: DiptoChakrabarty <diptochuck123@gmail.com>

pkg/notifier/gchat_test.go

@@ -18,7 +18,7 @@ package notifier
 
 import (
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -34,7 +34,7 @@ func TestGChat_Post(t *testing.T) {
 	}
 
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		b, err := ioutil.ReadAll(r.Body)
+		b, err := io.ReadAll(r.Body)
 		require.NoError(t, err)
 
 		var payload = GChatPayload{}