Update opentelemetry-semantic-conventions requirement from 0.28 to 0.29

Updates the requirements on [opentelemetry-semantic-conventions](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-semantic-conventions-0.28.0...opentelemetry-semantic-conventions-0.29.0)

---
updated-dependencies:
- dependency-name: opentelemetry-semantic-conventions
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -39,7 +39,7 @@ opentelemetry = { version = "0.28", default-features = false, features = [
   "trace",
 ] }
 opentelemetry-prometheus = { version = "0.28", optional = true }
-opentelemetry-semantic-conventions = { version = "0.28", features = [
+opentelemetry-semantic-conventions = { version = "0.29", features = [
   "semconv_experimental",
 ] }
 opentelemetry_sdk = { version = "0.28", optional = true, features = [