Bumps [opentelemetry_sdk](https://github.com/open-telemetry/opentelemetry-rust) from 0.21.1 to 0.21.2.
- [Release notes](https://github.com/open-telemetry/opentelemetry-rust/releases)
- [Commits](https://github.com/open-telemetry/opentelemetry-rust/compare/v0.21.1...v0.21.2

)

---
updated-dependencies:
- dependency-name: opentelemetry_sdk
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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