fix _validate_concurrency

Author: Mantisus

src/crawlee/autoscaling/_concurrency_system.py

@@ -31,9 +31,9 @@
 
 
 def _validate_concurrency(value: int, name: str) -> int:
-    """Check that a retuned concurrency bound is an integer of at least 1."""
-    if not isinstance(value, int) or value < 1:
-        raise ValueError(f'{name} must be an integer of at least 1')
+    """Check that a retuned concurrency bound is at least 1."""
+    if value < 1:
+        raise ValueError(f'{name} must be at least 1')
 
     return value