Mark 120 deprecated API operations with deprecated: true

Adds the OpenAPI `deprecated: true` field to all deprecated operations
(Bot Users, Backends, Edges, Tunnels) so that Mintlify and other
consumers can render deprecation indicators natively.

Companion to ngrok/ngrok-docs#2070.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: BPKelley