Fixed IndexError when accessing the container port info (#417)

Author: Nusnus

src/pytest_celery/api/container.py

@@ -98,6 +98,12 @@ def ready_prompt(self) -> str | None:
         """
         return None
 
+    @retry(
+        stop=stop_after_attempt(3),
+        wait=wait_fixed(3),
+        retry=retry_if_exception_type(IndexError),
+        reraise=True,
+    )
     def _wait_port(self, port: str) -> int:
         """Blocks until the specified port is ready.