Remove cache2.primal.net from default relays

Primal's cache relay uses a proprietary protocol that doesn't support
standard Nostr filters (kinds, authors). It was returning NOTICE errors
("kinds or authors filter is not supported") for every query, causing
unnecessary noise and potential issues.

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/lib/appRelays.ts

@@ -15,7 +15,6 @@ export const APP_RELAYS: RelayMetadata = {
     { url: 'wss://relay.primal.net', read: true, write: true },
     { url: 'wss://relay.damus.io', read: true, write: true },
     { url: 'wss://nos.lol', read: true, write: true },
-    { url: 'wss://cache2.primal.net/v1', read: true, write: false },
   ],
   updatedAt: 0,
 };