fix(careers): remove /careers redirect so the in-app page is reachable (#5320)

A pre-existing permanent redirect /careers -> jobs.ashbyhq.com/sim shadowed the
new first-party careers page (#5316), sending visitors straight to the Ashby
board. Drop it so /careers serves the in-app page (which itself pulls the Ashby
roles).

apps/sim/next.config.ts

@@ -307,11 +307,6 @@ const nextConfig: NextConfig = {
         source: '/team',
         destination: 'https://cal.com/emirkarabeg/sim-team',
         permanent: false,
-      },
-      {
-        source: '/careers',
-        destination: 'https://jobs.ashbyhq.com/sim',
-        permanent: true,
       }
     )