ultralytics 8.0.105 classification hyp fix and new onplot callbacks (#2684)

Co-authored-by: ayush chaurasia <ayush.chaurarsia@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Ivan Shcheklein <shcheklein@gmail.com>

tests/conftest.py

@@ -0,0 +1,19 @@
+import pytest
+
+
+def pytest_addoption(parser):
+    parser.addoption('--runslow', action='store_true', default=False, help='run slow tests')
+
+
+def pytest_configure(config):
+    config.addinivalue_line('markers', 'slow: mark test as slow to run')
+
+
+def pytest_collection_modifyitems(config, items):
+    if config.getoption('--runslow'):
+        # --runslow given in cli: do not skip slow tests
+        return
+    skip_slow = pytest.mark.skip(reason='need --runslow option to run')
+    for item in items:
+        if 'slow' in item.keywords:
+            item.add_marker(skip_slow)