[libc++][chrono][test] Fixes bogus loops. (#101890)

Changes the loop range to match similar tests and avoids zero
iterations. The original motivation to reduce the number of iterations
was to allow the test to be executed during constant evaluation.

Fixes: llvm/llvm-project#100502
NOKEYCHECK=True
GitOrigin-RevId: 642259a2f21feffb0dc048162b4ce40b1e5a303d

Author: mordante

test/std/time/time.cal/time.cal.ymdlast/time.cal.ymdlast.nonmembers/comparisons.pass.cpp

@@ -59,8 +59,8 @@ constexpr bool test() {
                                 : std::strong_ordering::greater)));
 
   //  same month, different years
-  for (int i = 1000; i < 20; ++i)
-    for (int j = 1000; j < 20; ++j)
+  for (int i = 1000; i < 1010; ++i)
+    for (int j = 1000; j < 1010; ++j)
       assert((testOrder(year_month_day_last{year{i}, month_day_last{January}},
                         year_month_day_last{year{j}, month_day_last{January}},
                         i == j  ? std::strong_ordering::equal