`LightDataFetcher` implementation not getting executed as intended

[shalearkane]

Describe the bug
This condition in ExecutionStrategy:invokeDataFetcher():

if (dataFetcher instanceof LightDataFetcher) {

is evaluating to False even if the dataFetcher is actually created by implementing LightDataFetcher interface.

I have tried to debug why it is so, and I found this object being passed as datafetcher to the invokeDataFetcher function which is being evaluated as not a LightDataFetcher:

Context
I am creating a LightOperationExecutor as a lightweight alternative to OperationExecutor in GraphQL-SPQR by implementing LightDataFetcher. Open PR #502

To Reproduce
To reproduce, checkout commit 05642488bc and run test in Maven. You should see the tests SchemaTest.testSchema and RelayTest.testRelayMutations produce errors.

Note that even though the commit uses GraphQL-Java 21.3, this is also reproducible on 22.1 (latest), however in this situation we have this datafetcher object,

[shalearkane]

I think that this might not be bug if the intention behind LightDataFetcher is just to have an additional behavior of getting results if the environment is passed through a Supplier<> and should always have a way getting results as a regular ("heavy") datafetcher.