fix: Correct inverted return value in Scrapy scheduler enqueue_request

The enqueue_request method was returning bool(result.was_already_present),
which incorrectly returned True for duplicates and False for newly enqueued
requests. Per Scrapy's BaseScheduler contract, it should return True when
the request was successfully stored (new) and False when rejected (duplicate).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: vdusek

src/apify/scrapy/scheduler.py

@@ -136,7 +136,7 @@ def enqueue_request(self, request: Request) -> bool:
             raise
 
         logger.debug(f'rq.add_request result: {result}')
-        return bool(result.was_already_present)
+        return not bool(result.was_already_present)
 
     def next_request(self) -> Request | None:
         """Fetch the next request from the scheduler.