Change seed.radicle.garden -> iris.radicle.xyz — radicle-desktop

We were using a deprecated seed dns name.

         target="_blank">
         <DropdownListItem styleGap="0.5rem" styleWidth="100%" selected={false}>
           <Icon name="seed" />
           view on seed.radicle.garden
           view on iris.radicle.xyz
           <span style:margin-left="auto"><Icon name="open-external" /></span>
         </DropdownListItem>
       </a>

 export function explorerUrl(
   path: string,
   seed = "seed.radicle.garden",
   seed = "iris.radicle.xyz",
   explorer = "https://app.radicle.xyz",
 ) {
   return `${explorer}/nodes/${seed}/${path}`;