This PR essentially removes the logic I introduced in
https://github.com/zed-industries/zed/pull/45361 to position workspace
modals based on the pointer click coordinates. All of this code has
become unnecessary given in
https://github.com/zed-industries/zed/pull/45924 we made the remote,
project, and branch modals use popovers when triggered with a pointer,
which already handle all the anchored positioning based on the trigger
(much better).

Release Notes:

- N/A