v0.13.0-b4

L1 watcher: avoid "block range extends beyond current head block" errors

🐛 Fixes

• l1-watcher: leave 2 confirmation blocks unprocessed - matching the upgrade watcher's behavior. (a74e335)
• integration test fix: add the missing private API server config, and bind it to a dynamically allocated port. (1f63f2b)

Full Changelog: v0.13.0-b2...v0.13.0-b4