ssh remoting: Use matching versions of remote server binary (#19740)

This changes the download logic to not fetch the latest version, but to
fetch the version matching the current version of Zed.


Release Notes:

- Changed the update logic of the SSH remote server to not fetch the
latest version for a current channel, but to fetch the version matching
the current Zed version. If Zed is updated, the server is updated too.
If the server is newer than the Zed version an error will be displayed.