fix(fathom): mark calendar_invitees email optional in list_meetings outputs

Fathom's docs mark Invitee.email as nullable; the outputs schema now
reflects that instead of declaring it as always-present.

Author: waleedlatif1

apps/sim/tools/fathom/list_meetings.ts

@@ -254,7 +254,7 @@ export const listMeetingsTool: ToolConfig<FathomListMeetingsParams, FathomListMe
               type: 'object',
               properties: {
                 name: { type: 'string', description: 'Invitee name', optional: true },
-                email: { type: 'string', description: 'Invitee email' },
+                email: { type: 'string', description: 'Invitee email', optional: true },
                 email_domain: {
                   type: 'string',
                   description: 'Invitee email domain',