Fix LoadStreams final frame bug (#4387)

Co-authored-by: Nadim Bou Alwan <64587372+nadinator@users.noreply.github.com>

tests/conftest.py

@@ -1,7 +1,14 @@
 # Ultralytics YOLO 🚀, AGPL-3.0 license
 
+import shutil
+from pathlib import Path
+
 import pytest
 
+from ultralytics.utils import ROOT
+
+TMP = (ROOT / '../tests/tmp').resolve()  # temp directory for test files
+
 
 def pytest_addoption(parser):
     parser.addoption('--runslow', action='store_true', default=False, help='run slow tests')
@@ -19,3 +26,21 @@ def pytest_collection_modifyitems(config, items):
     for item in items:
         if 'slow' in item.keywords:
             item.add_marker(skip_slow)
+
+
+def pytest_sessionstart(session):
+    """
+    Called after the 'Session' object has been created and before performing test collection.
+    """
+    shutil.rmtree(TMP, ignore_errors=True)  # delete any existing tests/tmp directory
+    TMP.mkdir(parents=True, exist_ok=True)  # create a new empty directory
+
+
+def pytest_terminal_summary(terminalreporter, exitstatus, config):
+    # Remove files
+    for file in ['bus.jpg', 'decelera_landscape_min.mov']:
+        Path(file).unlink(missing_ok=True)
+
+    # Remove directories
+    for directory in ['.pytest_cache/', TMP]:
+        shutil.rmtree(directory, ignore_errors=True)