tests/py: Add helpers for figuring out if tests run in CI or containers

Which is useful for skipping test with the @pytest.mark.skipif
decorator.

tests/__init__.py

@@ -9,6 +9,7 @@
 from itertools import count
 from typing import Any, Dict, Optional, NamedTuple, Callable
 
+import os
 import dbus
 import dbus.proxies
 import dbusmock
@@ -27,6 +28,17 @@
 logger = logging.getLogger("tests")
 
 
+def is_in_ci() -> bool:
+    return os.environ.get("XDP_TEST_IN_CI") is not None
+
+
+def is_in_container() -> bool:
+    return is_in_ci() or (
+        "container" in os.environ
+        and (os.environ["container"] == "docker" or os.environ["container"] == "podman")
+    )
+
+
 def wait(ms: int):
     """
     Waits for the specified amount of milliseconds.

tests/test_usb.py

@@ -188,17 +188,7 @@ def cb_device_events(session_handle, events):
             )
 
     @pytest.mark.parametrize("usb_queries", ["vnd:04a9", None])
-    @pytest.mark.skipif(
-        ("GITHUB_ACTIONS" in os.environ and os.environ["GITHUB_ACTIONS"] == "true")
-        or (
-            "container" in os.environ
-            and (
-                os.environ["container"] == "docker"
-                or os.environ["container"] == "podman"
-            )
-        ),
-        reason="Test fail in containers",
-    )
+    @pytest.mark.skipif(xdp.is_in_container(), reason="Test fail in containers")
     def test_device_remove(self, portals, dbus_con, app_id, usb_queries, umockdev):
         usb_intf = xdp.get_portal_iface(dbus_con, "Usb")