kitty @ launch cannot use --env flag with --cwd current over SSH

[AprilArcus]

Description
Since 0.28.x (7c8c7fe) it has been possible to use kitty @ launch --cwd=current on a remote machine to open a process using a shared SSH session.

When running in this manner, however, the --env flag becomes a no-op.

Reproduction

ssh some_remote
kitty @ launch --cwd current --env foo=bar zsh
if [ -z $foo ]; then echo fail; else; echo win; fi

should print win.