The simple answer is no. Mission: Impossible — The Final Reckoning does not have a post-credits scene. So, you will not be missing anything if you leave during the credits.

Even Benji is there. Things looked dire for him in the control room, but he survived the gunshot and appears to be back in full strength at the end of The Final Reckoning.

The movie could be the end of a franchise 30 years in the making. Here's the ending to Mission: Impossible — The Final Reckoning.