re-enable serverless tests

Author: baileympearson

.evergreen/config.yml

@@ -3720,6 +3720,14 @@ buildvariants:
       - run-custom-csfle-tests-rapid
       - run-custom-csfle-tests-latest
       - test-latest-driver-mongodb-client-encryption-6.0.0
+  - name: rhel8-test-serverless
+    display_name: Serverless Test
+    run_on: rhel80-large
+    expansions:
+      NODE_LTS_VERSION: 16
+      NPM_VERSION: 9
+    tasks:
+      - serverless_task_group
   - name: rhel8-test-gcp-kms
     display_name: GCP KMS Test
     run_on: debian11-small

.evergreen/generate_evergreen_tasks.js

@@ -806,17 +806,16 @@ BUILD_VARIANTS.push({
   tasks: customDependencyTests.map(({ name }) => name)
 });
 
-// TODO(NODE-6786): Reenable serverless testing.
-// BUILD_VARIANTS.push({
-//   name: 'rhel8-test-serverless',
-//   display_name: 'Serverless Test',
-//   run_on: DEFAULT_OS,
-//   expansions: {
-//     NODE_LTS_VERSION: LOWEST_LTS,
-//     NPM_VERSION: 9
-//   },
-//   tasks: ['serverless_task_group']
-// });
+BUILD_VARIANTS.push({
+  name: 'rhel8-test-serverless',
+  display_name: 'Serverless Test',
+  run_on: DEFAULT_OS,
+  expansions: {
+    NODE_LTS_VERSION: LOWEST_LTS,
+    NPM_VERSION: 9
+  },
+  tasks: ['serverless_task_group']
+});
 
 BUILD_VARIANTS.push({
   name: 'rhel8-test-gcp-kms',