remove

src/cmd/completion.go

@@ -43,7 +43,7 @@ fish:
   $ %[1]s completion fish > ~/.config/fish/completions/%[1]s.fish
 `, rootCmd.Name()),
 	DisableFlagsInUseLine: true,
-	ValidArgs:             []string{"bash", "zsh", "fish", "powershell"},
+	ValidArgs:             []string{"bash", "zsh", "fish"},
 	Args:                  cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
 	Run: func(cmd *cobra.Command, args []string) {
 		switch args[0] {