[videos] Fix saving imdb_id duplicates

tests/videos_tests/test_video_find_or_create.py

@@ -0,0 +1,17 @@
+import pytest
+from videos.models import Video
+
+
+@pytest.mark.django_db
+class TestVideoFindOrCreate:
+    def test_find_or_create_with_none_returns_none(self):
+        result = Video.find_or_create(None)
+        assert result is None
+
+    def test_find_or_create_with_empty_string_returns_none(self):
+        result = Video.find_or_create("")
+        assert result is None
+
+    def test_find_or_create_with_invalid_id_returns_none(self):
+        result = Video.find_or_create("invalid-id")
+        assert result is None