Fix end time of clips (#5255)

Closes #5256
Authored by: cruel-efficiency

yt_dlp/YoutubeDL.py

@@ -2720,7 +2720,8 @@ class YoutubeDL:
                 if chapter or offset:
                     new_info.update({
                         'section_start': offset + chapter.get('start_time', 0),
-                        'section_end': end_time if end_time < offset + duration else None,
+                        # duration may not be accurate. So allow deviations <1sec
+                        'section_end': end_time if end_time <= offset + duration + 1 else None,
                         'section_title': chapter.get('title'),
                         'section_number': chapter.get('index'),
                     })