Update opentelemetry-otlp requirement from 0.16 to 0.26

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-0.16.0...opentelemetry-otlp-0.16.0)

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

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

Cargo.toml

@@ -72,7 +72,7 @@ opentelemetry = "0.23"
 opentelemetry_sdk = { version = "0.23", features = ["rt-tokio"] }
 parking_lot = { version = "0.12", features = ["arc_lock", "nightly"] }
 garde = { version = "0.20", features = ["derive", "email", "email-idna"] }
-opentelemetry-otlp = { version = "0.16", features = ["grpc-tonic", "metrics"] }
+opentelemetry-otlp = { version = "0.26", features = ["grpc-tonic", "metrics"] }
 tracing-subscriber = { version = "0.3", features = [
     "parking_lot",
     "env-filter",