fix: return type in get_service_port docstring

Author: PraneethJain

core/testcontainers/compose/compose.py

@@ -484,7 +484,7 @@ def get_service_port(
 
         Returns
         -------
-        str:
+        int:
             The mapped port on the host
         """
         normalize: PublishedPortModel = self.get_container(service_name).get_publisher(by_port=port).normalize()