fix: remove unresolvable redactable dep to unblock CI

redactable ^0.1.0 was added to pyproject.toml before the package was
published to PyPI, making it impossible to regenerate poetry.lock and
breaking all CI jobs. The codebase already imports it via importlib with
a documented fallback for when it is unavailable, so removing it from
the required deps is safe and matches the actual runtime behaviour.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AhwicpfSvKesuRxBHs9sQ2

Author: claude

pyproject.toml

@@ -25,7 +25,6 @@ fastapi = ">=0.115"
 omegaconf = "^2.3"
 prometheus-client = "^0.25.0"
 cryptography = ">=44,<49"
-redactable = "^0.1.0"
 
 [tool.poetry.group.dev.dependencies]
 pytest = "^7.4"