There's also a first day that all clubs are legally allowed to start training camp. It doesn't mean they must start on that day. Similarly, they don't have to end on this date.
Widge showed you the proof of when camp ended. You're ignoring it.
There's a specific amount of extra practice time allowed during camps, that's why the NFL regulates how many and when OTAs, minicamps, and training camps occur. It's to mandate the maximum, not to force teams to have the same schedule. Teams have no obligation to use the full time, start on the same day or end on the same day. They can end camp early and return to the less rigorous game week schedule whenever they want.
Edit:
According to this article from WDSU, training camp technically ended August 16.
https://www.wdsu.com/article/new-orleans-saints-training-camp-2024/61194971
"The New Orleans Saints will begin this year's training camp on July 24 in Irvine, California. Rookies will report three days earlier on July 21.
Training camp runs for nearly four weeks and will end on Friday, Aug. 16."