Handle "webp" images for which their originally uploaded image was NOT of type "webp".
Twitter/X seems to be using some A/B Testing (Optimizely, Wikipedia) regarding images.
Some users receive embedded images coded as webp (smaller size = more efficient) even if the originally uploaded image was of another type (like jpg or png).
This makes it hard for the script to determine the link to the original image.
I as author of this script currently seem to be in the "B" group - I do not receive any "webp" images!
Nonetheless, I've developed a new version if this script (4.0) to try to deal with this "webp" scenario - but full validation testing is obviously difficult...
I ask for all who are in the "A" group - i.e. all who do receive "webp" images - to please test this script and to provide extensive feedback if things do break...