Fix the failing test in the server-aws-lambda

Since we upgraded Deno, along came a newer version of Tokio, which made a (breaking change)[tokio-rs/tokio#5766] to make `EnterGuard` `!Send`. We need to use `Handle::current()` to get the current handle so those dynamically loaded libraries will work with the same runtime (see comments in subsystem_resolver.rs).

Only one test in the server-aws-lambda crate was using the dynamically loaded library, so we fixed
by using static loaders, instead.

Filed #868

crates/core-subsystem/core-resolver/src/plugin/subsystem_resolver.rs

@@ -43,7 +43,9 @@ pub trait SubsystemResolver: Sync {
         request_context: &'a RequestContext,
         system_resolver: &'a SystemResolver,
     ) -> Result<Option<QueryResponse>, SubsystemResolutionError> {
-        // let _guard = handle.enter();
+        // TODO: reintroduce `let _guard = handle.enter();` or an equivalent mechanism to
+        // ensure dynamically loaded resolvers continue to work
+        // See issue #868
         self.resolve(operation, operation_type, request_context, system_resolver)
             .await
     }
@@ -57,7 +59,7 @@ pub trait SubsystemResolver: Sync {
         request_context: &'a RequestContext<'a>,
         system_resolver: &'a SystemResolver,
     ) -> Result<Option<QueryResponse>, SubsystemResolutionError> {
-        // let _guard = handle.enter();
+        // TODO: See above for `let _guard = handle.enter();` reintroduction
         self.invoke_interceptor(
             interceptor_index,
             intercepted_operation,

crates/server-aws-lambda/tests/common.rs

@@ -14,6 +14,7 @@ use std::sync::Arc;
 use resolver::create_system_resolver_from_serialized_bytes;
 use serde_json::Value;
 use server_aws_lambda::resolve;
+use server_common::create_static_loaders;
 
 pub async fn test_query(json_input: Value, exo_model: &str, expected: Value) {
     let context = lambda_runtime::Context::default();
@@ -29,7 +30,7 @@ pub async fn test_query(json_input: Value, exo_model: &str, expected: Value) {
         .await
         .unwrap();
     let system_resolver = Arc::new(
-        create_system_resolver_from_serialized_bytes(model_system, vec![])
+        create_system_resolver_from_serialized_bytes(model_system, create_static_loaders())
             .await
             .unwrap(),
     );