don't kill all server sessions for the atlas full tests

Author: jamis

.evergreen/run-tests-atlas-full.sh

@@ -13,7 +13,7 @@ set_env_ruby
 bundle_install
 
 ATLAS_URI=$MONGODB_URI \
-  SERVERLESS=1 \
+  KILL_ALL_SERVER_SESSIONS=0 \
   EXAMPLE_TIMEOUT=600 \
   bundle exec rspec -fd spec/integration/search_indexes_prose_spec.rb
 

spec/support/spec_config.rb

@@ -163,7 +163,8 @@ def ocsp_connectivity?
   end
 
   def kill_all_server_sessions?
-    ClusterConfig.instance.fcv_ish >= '3.6'
+    allow = ENV['KILL_ALL_SERVER_SESSIONS'] != '0'
+    allow && ClusterConfig.instance.fcv_ish >= '3.6'
   end
 
   # Test suite configuration