chore(deps): update opentelemetry-otlp requirement from 0.13.0 to 0.15.0

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)
- [Commits](open-telemetry/opentelemetry-rust@opentelemetry-otlp-0.13.0...opentelemetry-otlp-0.13.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Cargo.toml

@@ -25,7 +25,7 @@ uuid = { version = "1.3", features = ["serde", "v4"] }
 tracing = "0.1"
 tracing-subscriber = { version = "0.3.16", features = ["env-filter", "json"] }
 tracing-opentelemetry = "0.20.0"
-opentelemetry-otlp = { version = "0.13.0", features = ["http-proto", "reqwest-client"] }
+opentelemetry-otlp = { version = "0.15.0", features = ["http-proto", "reqwest-client"] }
 opentelemetry = { version = "0.20.0", features = ["trace", "rt-tokio"]}
 opentelemetry-semantic-conventions = "0.12.0"
 opentelemetry-http = "0.9.0"