Update list of Snowflake STUN servers in default bridge line, 2026 edition

A merge request will be provided by issue author

We are currently in the process of replacing broken STUN server that don't correctly support NAT Type discovery(or interactive connectivity type discovery) with tested and validated servers. The following change has already been deployed with circumvention settings since 3 weeks ago with no known incidents.

The server that is being added:

• stun.telnyx.com:3478
• stun.hot-chilli.net:3478
• stun.fitauto.ru:3478
• stun.m-online.net:3478

The server that is being removed:

• stun.nextcloud.com:3478
• stun.bethesda.net:3478
• stun.nextcloud.com:443

See also(content selectively copied to here): tpo/anti-censorship/rdsys-admin!47 (merged)