ovn: fix update script

Declaring type on boolean arguments is no longer supported by nushell

pkgs/by-name/ov/ovn/update.nu

@@ -1,7 +1,7 @@
 #!/usr/bin/env nix-shell
 #!nix-shell -i nu -p nushell common-updater-scripts
 
-def main [--lts: bool = false, --regex: string] {
+def main [--lts = false, --regex: string] {
   let tags = list-git-tags --url=https://github.com/ovn-org/ovn | lines | sort --natural | str replace v ''
 
   let latest_tag = if $regex == null { $tags } else { $tags | find --regex $regex } | last