test(matrix): skip cleanly when optional deps are missing

tests/channels/test_matrix_channel.py

@@ -3,16 +3,14 @@ from pathlib import Path
 from types import SimpleNamespace
 
 import pytest
+
+pytest.importorskip("nio")
+pytest.importorskip("nh3")
+pytest.importorskip("mistune")
 from nio import RoomSendResponse
 
 from nanobot.channels.matrix import _build_matrix_text_content
 
-# Check optional matrix dependencies before importing
-try:
-    import nh3  # noqa: F401
-except ImportError:
-    pytest.skip("Matrix dependencies not installed (nh3)", allow_module_level=True)
-
 import nanobot.channels.matrix as matrix_module
 from nanobot.bus.events import OutboundMessage
 from nanobot.bus.queue import MessageBus