Fix yolo checks as a package bug in Colab (#972)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Sergio Sanchez <sergio.ssm.97@gmail.com>

tests/test_python.py

@@ -1,5 +1,6 @@
 # Ultralytics YOLO 🚀, GPL-3.0 license
 
+import platform
 from pathlib import Path
 
 import cv2
@@ -14,6 +15,7 @@ from ultralytics.yolo.utils import ROOT, SETTINGS
 MODEL = Path(SETTINGS['weights_dir']) / 'yolov8n.pt'
 CFG = 'yolov8n.yaml'
 SOURCE = ROOT / 'assets/bus.jpg'
+MACOS = platform.system() == 'Darwin'  # macOS environment
 
 
 def test_model_forward():
@@ -120,10 +122,11 @@ def test_export_openvino():
     YOLO(f)(SOURCE)  # exported model inference
 
 
-def test_export_coreml():
+def test_export_coreml():  # sourcery skip: move-assign
     model = YOLO(MODEL)
-    model.export(format='coreml')
-    # YOLO(f)(SOURCE)  # model prediction only supported on macOS
+    f = model.export(format='coreml')
+    if MACOS:
+        YOLO(f)(SOURCE)  # model prediction only supported on macOS
 
 
 def test_export_paddle(enabled=False):