chore(deps): update metrics requirement in /veza-chat-server

Updates the requirements on [metrics](https://github.com/metrics-rs/metrics) to permit the latest version.
- [Changelog](https://github.com/metrics-rs/metrics/blob/main/release.toml)
- [Commits](https://github.com/metrics-rs/metrics/compare/metrics-v0.22.0...metrics-v0.24.3)

---
updated-dependencies:
- dependency-name: metrics
  dependency-version: 0.24.3
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

veza-chat-server/Cargo.toml

@@ -119,7 +119,7 @@ clap = { version = "4.4", features = ["derive", "env"] } # CLI arguments
 # ═══════════════════════════════════════════════════════════════════════
 # PERFORMANCE ET MONITORING
 # ═══════════════════════════════════════════════════════════════════════
-metrics = { version = "0.22", optional = true }                # Métriques de performance
+metrics = { version = "0.24", optional = true }                # Métriques de performance
 metrics-exporter-prometheus = { version = "0.13", optional = true }  # Export Prometheus
 dashmap = "6.1"                 # HashMap concurrent
 parking_lot = "0.12"            # Mutex plus performants