fix(azure-functions): only use return in InvocationContext.options if set (#4509)

https://github.com/Azure/azure-functions-nodejs-library/blob/138c0215136da5b19b879554da3468028426911e/types/InvocationContext.d.ts#L320
shows that the `InvocationContext.options.return` is optional.

Closes: #4508
Co-authored-by: Trent Mick <[email protected]>

Author: wladimirguerra

lib/instrumentation/azure-functions.js

@@ -376,7 +376,9 @@ function instrument(agent) {
         direction: context?.options?.trigger?.direction,
       });
       // Output bindings
-      bindingDefinitions.push(context?.options?.return);
+      if (context?.options?.return) {
+        bindingDefinitions.push(context?.options?.return);
+      }
     }
     let executionContext = context.executionContext;
     if (!executionContext) {