Last time I checked, this wasn’t possible, even on Pixel devices.
I mean the nagging popup that offers to Edit or Share each time you take a screenshot. Picture here, https://support.google.com/assistant/thread/72784431/disable-screenshot-popup-in-android-11
It obscures part of the display and is a general time waster. Maybe make disabling it optional? Should be relevant for all Android 11 devices.
Regain your privacy! Adopt /e/ the unGoogled mobile OS and online services
sure it is annoying
but to call it a time waster just because you have to wait a second or two in your life is an exaggeration… 
It’s a waste of time typing and reading that answer…
For completeness, this nuisance popup also happens on Android 10.
+1
I know I could do without the popup!
Maybe ask Google then. It’s clearly not an /e/OS introduced item nor Lineage.
To want to have someone go deep into the code to get rid of something that may annoy is a bit unrealistic. IMNSHO.
Then of course there’s the “The source is available. Have at it.” thing.
Although I do consider the change from being in the notification shade to a popup unnecessary, and yes annoying, it has come in handy in that I usually send screenshots through Send Reduced and then Phone Saver via that popup. Or a quick crop. Saving me extra steps of having to open Gallery first and going to the image.
What is a waste of time for one may be a time saver for another.
BTW, you know there is a little ‘x’ on the popup so you can immediately get rid of it. No time wasting then, yeah?