Fix "doesn't exists" typo (#26307)

server/channels/app/import_functions_test.go

@@ -1588,7 +1588,7 @@ func TestImportUserTeams(t *testing.T) {
 			expectedUserChannels: 0,
 		},
 		{
-			name: "Should fail if one of the roles doesn't exists",
+			name: "Should fail if one of the roles doesn't exist",
 			data: &[]imports.UserTeamImportData{
 				{
 					Name:  &th.BasicTeam.Name,
@@ -1810,7 +1810,7 @@ func TestImportUserChannels(t *testing.T) {
 			expectedUserChannels: 0,
 		},
 		{
-			name: "Should fail if one of the roles doesn't exists",
+			name: "Should fail if one of the roles doesn't exist",
 			data: &[]imports.UserChannelImportData{
 				{
 					Name:  &th.BasicChannel.Name,