Fix Flashing Hover Popover (#8238)

Release Notes:

- Use an inclusive range for local range containment check to match LSP
behavior & fix popover flashing while the cursor moves over the last
character of a symbol.


https://github.com/zed-industries/zed/assets/17223924/6c3ddc9c-04fb-4414-812f-025ede5ecaf7