Disable password authentication when using keys

Fixes #2687

tmt/steps/provision/__init__.py

@@ -1278,6 +1278,13 @@ def _ssh_options(self) -> Command:
  options.extend(['-i', key])
  if self.password:
  options.extend(['-oPasswordAuthentication=yes'])
+ else:
+ # Makes sure the connection is rejected when we want key-
+ # based authetication only instead of presenting a prompt
+ # Prevents issues like https:/teemtee/tmt/issues/2687
+ # from happening and makes the ssh connection more robust
+ # by allowing proper re-try mechanisms to kick-in
+ options.extend(['-oPasswordAuthentication=no'])
 
  # Use the shared master connection
  options.append(f'-S{self._ssh_socket()}')