enable linux_nightly_main_enabled

Author: sebsto

.github/workflows/pull_request.yml

@@ -29,7 +29,7 @@ jobs:
       linux_nightly_next_enabled: true
       # this currently resolves to 6.2.dev
       # It crashes some of our tests https://github.com/swift-server/swift-aws-lambda-runtime/issues/509
-      linux_nightly_main_enabled: false
+      linux_nightly_main_enabled: true
 
   integration-tests:
     name: Integration Tests