v0.20.2

Fixed

• Restored compatibility with Rust 1.89 by updating gRPC, Redis, SQLx and
  serde_json integrations to avoid deprecated APIs, unsafe environment
  mutations and Debug requirements that no longer hold.
• Added deterministic backtrace preference overrides for unit tests so
  telemetry behavior remains covered without mutating global environment
  variables.
• Ensured config error mapping gracefully handles new non-exhaustive variants
  by falling back to a generic context that captures the formatted error.