PYTHON-1645 Only test zSeries on RHEL 7.2

Author: ShaneHarvey

.evergreen/config.yml

@@ -939,11 +939,6 @@ axes:
  run_on: rhel72-zseries-test
  batchtime: 10080 # 7 days
 
- - id: suse12-zseries-test
- display_name: "SUSE 12 (zSeries)"
- run_on: suse12-zseries-test
- batchtime: 10080 # 7 days
-
  - id: ubuntu1604-arm64-small
  display_name: "Ubuntu 16.04 (ARM64)"
  run_on: ubuntu1604-arm64-small
@@ -954,11 +949,6 @@ axes:
  run_on: ubuntu1604-power8-test
  batchtime: 10080 # 7 days
 
- - id: ubuntu1604-zseries-small
- display_name: "Ubuntu 16.04 (zSeries)"
- run_on: ubuntu1604-zseries-small
- batchtime: 10080 # 7 days
-
  - id: topology
  display_name: Topology
  values: