asim: delete redundant/not-really-useful tests

This commit deletes a few redundant or not-really-useful tests.

1. For constraint_satisfaction1, the test sets up a 9-node cluster across 4
   regions (a, b, c, d) with 3, 2, 1, and 3 nodes respectively. It creates 100
   ranges with 5 replicas each, initially placed on stores s1(a), s2(a), s4(b),
   s5(b), and s6(c). The span config requires 2 replicas in region a, 2 in
   region b, and 1 in region c, with lease preferences for region a, so all
   constraints were already satisfied. The generated load was not very
   interesting either.  We will likely need a similar test in the future, but
   this version is removed in favor of writing a better one later.

2. For constraint_satisfaction2, it appears to be leftover setup that used rebalance mode 0
   with other queues disabled, predating the introduction of configurations.

3. For constraint_satisfaction_old_alloc, it also seems to be leftover and is roughly the same as
   constraint_satisfaction1.txt.

4. high_cpu_skewed_placement.txt appears redundant with high_cpu.txt, which also
   uses skewed range placement on s1–3 with load targeting that keyspace. The
   only difference is an additional CPU workload evenly distributed across
   nodes, but it doesn’t test anything meaningfully different. In addition, the test
   set-up was wrong, and the load was hammering only one range.

5. load_distribution_movement_disabled_enable_later.txt was intended to test the
   switch between SMA and MMA mode, but the setup does not create an interesting
   scenario. We will likely need a similar test in the future, but this version
   is removed in favor of writing a better one later.

Author: wenyihu6