deps(deps): update opentelemetry-otlp requirement from 0.26 to 0.31

Updates the requirements on [opentelemetry-otlp](https://github.com/open-telemetry/opentelemetry-rust) to permit the latest version.
- [Release notes](https://github.com/open-telemetry/opentelemetry-rust/releases)
- [Changelog](https://github.com/open-telemetry/opentelemetry-rust/blob/main/docs/release_0.30.md)
- [Commits](open-telemetry/opentelemetry-rust@opentelemetry-otlp-0.26.0...v0.31.0)

---
updated-dependencies:
- dependency-name: opentelemetry-otlp
  dependency-version: 0.31.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -43,7 +43,7 @@ serde_json = "1.0"
 metrics = "0.24"
 metrics-exporter-prometheus = "0.16"
 opentelemetry = "0.26"
-opentelemetry-otlp = { version = "0.26", features = ["tokio", "tonic"] }
+opentelemetry-otlp = { version = "0.31", features = ["tokio", "tonic"] }
 opentelemetry_sdk = { version = "0.26", features = ["rt-tokio"] }
 tracing = "0.1"
 tracing-opentelemetry = "0.27"