If you look at the post in this thread by JulianSL on October 7, 2023 you will see he mentions double tapping the end workout button. I have forced myself to do this and I find that it works very close to 100% of the time. After a short time for me it has become muscle memory. Just need for your hand and the watch to be fairly still.
I had hoped the finger tap feature that was added (double tapping the thumb and forefinger, requires series 9) would help with this but for this case it doesn't appear to work because there isn't a default response. In addition, for me it works less than 50% of the time.
This is the best that can be done until/unless Apple realizes what I would call the "error" of their ways.