src/sage/groups/perm_gps/permgroup_named.py: speed up a slow test

Fix the CI warning,

  2025-07-14T18:38:36.5676939Z ##[warning]slow doctest:
  2025-07-14T18:38:36.5679618Z     all(SmallPermutationGroup(n,k).id() == [n,k]
  2025-07-14T18:38:36.5681631Z         for n in [1..64] for k in [1..numgps(n)])  # long time (180s)
  2025-07-14T18:38:36.5683632Z Test ran for 67.66s cpu, 71.13s wall

by making two few improvements:

  * Move the "long time" tag to the right line.
  * Check only a random subset of (up to five) n and k, rather than
    n <= 64 and all possible k.

Author: orlitzky

src/sage/groups/perm_gps/permgroup_named.py

@@ -3505,16 +3505,24 @@ class SmallPermutationGroup(PermutationGroup_generic):
         Group of order 12 and GAP Id 4 as a permutation group
         sage: G.gens()
         ((4,5), (1,2), (3,4,5))
-        sage: G.character_table()                                                       # needs sage.rings.number_field
+        sage: G.character_table()  # needs sage.rings.number_field
         [ 1  1  1  1  1  1]
         [ 1 -1  1 -1  1 -1]
         [ 1 -1  1  1 -1  1]
         [ 1  1  1 -1 -1 -1]
         [ 2  0 -1 -2  0  1]
         [ 2  0 -1  2  0 -1]
         sage: def numgps(n): return ZZ(libgap.NumberSmallGroups(n))
-        sage: all(SmallPermutationGroup(n,k).id() == [n,k]
-        ....:     for n in [1..64] for k in [1..numgps(n)])  # long time (180s)
+        sage: # verify at most five n and k, randomly, to save time
+        sage: from random import sample
+        sage: ns = sample([1..64], 5)
+        sage: def ks(n):
+        ....:     ngps = numgps(n)
+        ....:     ssize = min(5, ngps)
+        ....:     return sample([1..ngps], ssize)
+        sage: all(SmallPermutationGroup(n,k).id() == [n,k]  # long time
+        ....:     for n in ns
+        ....:     for k in ks(n))
         True
         sage: H = SmallPermutationGroup(6,1)
         sage: H.is_abelian()