completions: extra space is added in zsh when completing paths

[istudyatuni]

Description

When completing paths for command like jj diff | (| means cursor), and when using dynamic completions in zsh, extra space is added: jj diff pkgs/ |

Probably this is problem with zsh itself?

Steps to Reproduce the Problem

1. Add to zsh config: source <(COMPLETE=zsh jj)
2. Type jj diff | at any jj repo with changes and press tab

Expected Behavior

Space is not added, like in bash/fish

Actual Behavior

Space is added

Specifications

• Platform: NixOS
• Version: 0.25
• Zsh version: 5.9

Also tested on macos

[yuja]

#5039