MM-27407 Return archived channels even if view archived config is false for sysadmin endpoints (#15149)

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/channel_test.go

@@ -969,15 +969,6 @@ func TestGetAllChannels(t *testing.T) {
 	defer th.TearDown()
 	Client := th.Client
 
-	var originalConfigVal bool
-	th.App.UpdateConfig(func(cfg *model.Config) {
-		originalConfigVal = *cfg.TeamSettings.ExperimentalViewArchivedChannels
-		*cfg.TeamSettings.ExperimentalViewArchivedChannels = true
-	})
-	defer th.App.UpdateConfig(func(cfg *model.Config) {
-		*cfg.TeamSettings.ExperimentalViewArchivedChannels = originalConfigVal
-	})
-
 	th.TestForSystemAdminAndLocal(t, func(t *testing.T, client *model.Client4) {
 		channels, resp := client.GetAllChannels(0, 20, "")
 		CheckNoError(t, resp)
@@ -1265,10 +1256,6 @@ func TestSearchAllChannels(t *testing.T) {
 	})
 	CheckNoError(t, groupErr)
 
-	th.App.UpdateConfig(func(cfg *model.Config) {
-		*cfg.TeamSettings.ExperimentalViewArchivedChannels = true
-	})
-
 	testCases := []struct {
 		Description        string
 		Search             *model.ChannelSearch