refactor(NODE-5741): use async io helpers

.evergreen/config.in.yml

@@ -200,6 +200,8 @@ functions:
       type: test
       params:
         working_dir: "src"
+        env:
+          MONGODB_NEW_CONNECTION: ${MONGODB_NEW_CONNECTION|false}
         timeout_secs: 300
         shell: bash
         script: |

.evergreen/config.yml

@@ -170,6 +170,8 @@ functions:
       type: test
       params:
         working_dir: src
+        env:
+          MONGODB_NEW_CONNECTION: ${MONGODB_NEW_CONNECTION|false}
         timeout_secs: 300
         shell: bash
         script: |
@@ -4552,6 +4554,42 @@ buildvariants:
       - test-3.6-server-noauth
       - test-3.6-replica_set-noauth
       - test-3.6-sharded_cluster-noauth
+  - name: rhel8-new-connection-tests
+    display_name: New Connection Tests
+    run_on: rhel80-large
+    expansions:
+      NODE_LTS_VERSION: 20
+      CLIENT_ENCRYPTION: true
+      MONGODB_NEW_CONNECTION: true
+    tasks:
+      - test-latest-server
+      - test-latest-replica_set
+      - test-latest-sharded_cluster
+      - test-rapid-server
+      - test-rapid-replica_set
+      - test-rapid-sharded_cluster
+      - test-7.0-server
+      - test-7.0-replica_set
+      - test-7.0-sharded_cluster
+      - test-6.0-server
+      - test-6.0-replica_set
+      - test-6.0-sharded_cluster
+      - test-5.0-server
+      - test-5.0-replica_set
+      - test-5.0-sharded_cluster
+      - test-4.4-server
+      - test-4.4-replica_set
+      - test-4.4-sharded_cluster
+      - test-4.2-server
+      - test-4.2-replica_set
+      - test-4.2-sharded_cluster
+      - test-4.0-server
+      - test-4.0-replica_set
+      - test-4.0-sharded_cluster
+      - test-3.6-server
+      - test-3.6-replica_set
+      - test-3.6-sharded_cluster
+      - test-latest-server-v1-api
   - name: rhel8-test-lambda
     display_name: AWS Lambda handler tests
     run_on: rhel80-large

.evergreen/generate_evergreen_tasks.js

@@ -728,6 +728,18 @@ BUILD_VARIANTS.push({
   tasks: AUTH_DISABLED_TASKS.map(({ name }) => name)
 });
 
+BUILD_VARIANTS.push({
+  name: 'rhel8-new-connection-tests',
+  display_name: 'New Connection Tests',
+  run_on: DEFAULT_OS,
+  expansions: {
+    NODE_LTS_VERSION: LATEST_LTS,
+    CLIENT_ENCRYPTION: true,
+    MONGODB_NEW_CONNECTION: true
+  },
+  tasks: BASE_TASKS.map(({ name }) => name)
+});
+
 BUILD_VARIANTS.push({
   name: 'rhel8-test-lambda',
   display_name: 'AWS Lambda handler tests',

.evergreen/run-tests.sh

@@ -63,4 +63,5 @@ export MONGODB_URI=${MONGODB_URI}
 export LOAD_BALANCER=${LOAD_BALANCER}
 export TEST_CSFLE=${TEST_CSFLE}
 export COMPRESSOR=${COMPRESSOR}
+export MONGODB_NEW_CONNECTION=${MONGODB_NEW_CONNECTION}
 npm run "${TEST_NPM_SCRIPT}"