Fix issue where service doesn't die when it doesn't have the necessary environment variables

[grymmy]

     |                                                      ^
   9 |
  10 | async function sendEmailWithLoops(
  11 |     transactionEmailId: string,
 ⨯ unhandledRejection:  Error: Please set LOOPS_TRANSACTIONAL_PERSONALIZED_EMAIL_ID
    at [project]/lib/loops.ts [app-rsc] (ecmascript) (file:/Users/graham/Work/shipwrecked/lib/loops.ts:8:54)
    at <unknown> (file:/Users/graham/Work/shipwrecked/app/api/auth/%5B...nextauth%5D/route.ts:9:0)
    at [project]/app/api/auth/[...nextauth]/route.ts [app-rsc] (ecmascript) (.next/server/chunks/ssr/[root of the server]__58deb630._.js:8554:1)
    at <unknown> (file:/Users/graham/Work/shipwrecked/app/rsvp/actions.ts:3:0)
    at [project]/app/rsvp/actions.ts [app-rsc] (ecmascript) (.next/server/chunks/ssr/[root of the server]__58deb630._.js:8909:1)
    at <unknown> (.next/server/chunks/ssr/[root of the server]__58deb630._.js:9134:148)
    at [project]/.next-internal/server/app/page/actions.js { ACTIONS_MODULE0 => "[project]/app/rsvp/actions.ts [app-rsc] (ecmascript)" } [app-rsc] (server actions loader, ecmascript) <module evaluation> (.next/server/chunks/ssr/[root of the server]__58deb630._.js:9132:1)
    at <unknown> (.next/server/chunks/ssr/[root of the server]__58deb630._.js:9166:365)
    at [project]/.next-internal/server/app/page/actions.js { ACTIONS_MODULE0 => "[project]/app/rsvp/actions.ts [app-rsc] (ecmascript)" } [app-rsc] (server actions loader, ecmascript) (.next/server/chunks/ssr/[root of the server]__58deb630._.js:9162:1)
    at Object.<anonymous> (.next/server/app/page.js:21:9)
   6 | if (!LOOPS_TRANSACTIONAL_SIGNIN_EMAIL_ID) throw new Error("Please set LOOPS_TRANSACTIONAL_SIGNIN_EMAIL_ID");
   7 | if (!LOOPS_TRANSACTIONAL_NOTIFICATION_EMAIL_ID) throw new Error("Please set LOOPS_TRANSACTIONAL_NOTIFICATION_EMAIL_ID");
>  8 | if (!LOOPS_TRANSACTIONAL_PERSONALIZED_EMAIL_ID) throw new Error("Please set LOOPS_TRANSACTIONAL_PERSONALIZED_EMAIL_ID");
     |                                                      ^
   9 |
  10 | async function sendEmailWithLoops(
  11 |     transactionEmailId: string,
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