fix: load completion files atomically (#14000)

Fixes #13964
 
Co-authored-by: Marc Cornellà <marc@mcornella.com>

plugins/docker/docker.plugin.zsh

@@ -56,7 +56,8 @@ if [[ ! -f "$ZSH_CACHE_DIR/completions/_docker" ]]; then
   _comps[docker]=_docker
 fi
 
-{
+zmodload -F zsh/files b:zf_mv
+() {
   # `docker completion` is only available from 23.0.0 on
   # docker version returns `Docker version 24.0.2, build cb74dfcd85`
   # with `s:,:` remove the comma after the version, and select third word of it
@@ -64,6 +65,7 @@ fi
     ! is-at-least 23.0.0 ${${(s:,:z)"$(command docker --version)"}[3]}; then
         command cp "${0:h}/completions/_docker" "$ZSH_CACHE_DIR/completions/_docker"
       else
-        command docker completion zsh | tee "$ZSH_CACHE_DIR/completions/_docker" > /dev/null
+        local TMPPREFIX="$ZSH_CACHE_DIR/completions/_docker"
+        zf_mv -f -- =( command docker completion zsh ) "$TMPPREFIX"
   fi
 } &|