DEV: removes unnecessary caret position code (PR #14665)

We don’t support any browser needing this for very long: "selectionStart" | Can I use... Support tables for HTML5, CSS3, etc

I’m keeping some protection so It doesn’t crash but ultimately element.selectionStart should be enough.

Im not removing this in the commit, but the caret_position.js file seems barely used.

GitHub

Looks good, and indeed, it doesn’t look like we are using the caret_position jQuery plugin.

Looks good, and indeed, it doesn’t look like we are using the caret_position jQuery plugin.

I said “barely” because I think it’s actually used: discourse/autocomplete.js at main · discourse/discourse · GitHub