Bump go.uber.org/zap from 1.20.0 to 1.21.0 in /pkg/otlp/model

Bumps [go.uber.org/zap](https://github.com/uber-go/zap) from 1.20.0 to 1.21.0.
- [Release notes](https://github.com/uber-go/zap/releases)
- [Changelog](https://github.com/uber-go/zap/blob/master/CHANGELOG.md)
- [Commits](uber-go/zap@v1.20.0...v1.21.0)

---
updated-dependencies:
- dependency-name: go.uber.org/zap
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

pkg/otlp/model/go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/stretchr/testify v1.7.0
 	go.opentelemetry.io/collector/model v0.44.0
-	go.uber.org/zap v1.20.0
+	go.uber.org/zap v1.21.0
 )
 
 require (