remove a test that consumes a lot of memory

This test consumes more memory than any of our other
tests, ending up with a heap size of 457MB:

    i17 : (GCstats())#"heap size"

    o17 = 456880128

Every other test and example runs with a heap size limited to 300MB. Removing
it may make it easier to build Macaulay2 on smallish virtual machines.