[MM-61499] Fix errcheck issues in server/channels/app/slashcommands/helper_test.go (#30880)

server/channels/app/slashcommands/command_me_test.go

@@ -13,7 +13,6 @@ import (
 
 func TestMeProviderDoCommand(t *testing.T) {
 	th := setup(t)
-	defer th.tearDown()
 
 	mp := MeProvider{}