test: remove batch time

Author: durran

.evergreen/config.yml

@@ -4069,7 +4069,6 @@ buildvariants:
   - name: rhel8-test-atlas
     display_name: Atlas Cluster Tests
     run_on: rhel80-large
-    batchtime: 20160
     tasks:
       - test_atlas_task_group
   - name: rhel8-no-auth-tests

.evergreen/generate_evergreen_tasks.js

@@ -757,7 +757,6 @@ BUILD_VARIANTS.push({
   name: 'rhel8-test-atlas',
   display_name: 'Atlas Cluster Tests',
   run_on: DEFAULT_OS,
-  batchtime: 20160,
   tasks: ['test_atlas_task_group']
 });