promql: disable some slow cases in TestConcurrentRangeQueries

TestConcurrentRangeQueries runs many queries, up to 4 at the same time,
to try to expose any race conditions.
This change stops four of them from running with a thousand or more steps:

  `holt_winters(a_X[1d], 0.3, 0.3)`
  `changes(a_X[1d])`
  `rate(a_X[1d])`
  `absent_over_time(a_X[1d])`

Particularly when the test runs with `-race` in CI, this reduces the
time and resources required.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

promql/promql_test.go

@@ -73,6 +73,9 @@ func TestConcurrentRangeQueries(t *testing.T) {
 		if strings.Contains(c.expr, "count_values") && c.steps > 10 {
 			continue // This test is too big to run with -race.
 		}
+		if strings.Contains(c.expr, "[1d]") && c.steps > 100 {
+			continue // This test is too slow.
+		}
 		<-sem
 		g.Go(func() error {
 			defer func() {