Flag '-use-local-tailscaled' enables funnel mode

[corvax19]

Hello,

When starting tsidp with -use-local-tailscaled, it is started with funnel mode:

root@tsidp:~# TAILSCALE_USE_WIP_CODE=1 tsidp -use-local-tailscaled -log debug
setting funnel for tsidp.scylla-hake.ts.net:443
2025/10/25 14:53:05 INFO tsidp server started server_url=https://tsidp.scylla-hake.ts.net
^C2025/10/25 14:53:16 INFO interrupt, exiting

Reproduced on 0203816