Simplify statsport fixture in statschannel test

The ports fixture provides the required port numbers already and there's
no need to get the port number from environment.

(cherry picked from commit f0481c8600)

bin/tests/system/statschannel/conftest.py

@@ -9,17 +9,9 @@
 # See the COPYRIGHT file distributed with this work for additional
 # information regarding copyright ownership.
 
-import os
 import pytest
 
 
-@pytest.fixture
-def statsport(request):
-    # pylint: disable=unused-argument
-    env_port = os.getenv("EXTRAPORT1")
-    if env_port is None:
-        env_port = 5301
-    else:
-        env_port = int(env_port)
-
-    return env_port
+@pytest.fixture(scope="module")
+def statsport(ports):
+    return ports["EXTRAPORT1"]