testsuite: disable "flux mini run --nodes=2 fails"

Problem: A test in the testsuite ensure that flux mini run --nodes=2
fails due to a "node count cannot be greater than task count" error,
but soon this usage will be allowed. (ntasks will default to nnodes
with exclusive flag set)

Remove the test to avoid breaking the testsuite.

t/t2700-mini-cmd.t

@@ -49,10 +49,6 @@ test_expect_success 'flux mini run --ntasks=1 --nodes=2 fails' '
 		2>run1n2N.err &&
 	grep -i "node count must not be greater than task count" run1n2N.err
 '
-test_expect_success 'flux mini run (default ntasks) --nodes=2 fails' '
-	test_must_fail flux mini run --nodes=2 hostname 2>run2N.err &&
-	grep -i "node count must not be greater than task count" run2N.err
-'
 test_expect_success 'flux mini submit --urgency=6 works' '
 	jobid=$(flux mini submit --urgency=6 hostname) &&
 	flux job eventlog $jobid | grep submit | grep urgency=6