[chore]: Bump go.opentelemetry.io/otel from 1.20.0 to 1.21.0 (#2369)

Bumps [go.opentelemetry.io/otel](https://github.com/open-telemetry/opentelemetry-go) from 1.20.0 to 1.21.0.
- [Release notes](https://github.com/open-telemetry/opentelemetry-go/releases)
- [Changelog](https://github.com/open-telemetry/opentelemetry-go/blob/main/CHANGELOG.md)
- [Commits](https://github.com/open-telemetry/opentelemetry-go/compare/v1.20.0...v1.21.0)

---
updated-dependencies:
- dependency-name: go.opentelemetry.io/otel
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

vendor/go.opentelemetry.io/otel/versions.yaml

@@ -14,13 +14,12 @@
 
 module-sets:
   stable-v1:
-    version: v1.20.0
+    version: v1.21.0
     modules:
       - go.opentelemetry.io/otel
       - go.opentelemetry.io/otel/bridge/opentracing
       - go.opentelemetry.io/otel/bridge/opentracing/test
       - go.opentelemetry.io/otel/example/dice
-      - go.opentelemetry.io/otel/example/fib
       - go.opentelemetry.io/otel/example/namedtracer
       - go.opentelemetry.io/otel/example/otel-collector
       - go.opentelemetry.io/otel/example/passthrough
@@ -35,14 +34,12 @@ module-sets:
       - go.opentelemetry.io/otel/sdk/metric
       - go.opentelemetry.io/otel/trace
   experimental-metrics:
-    version: v0.43.0
+    version: v0.44.0
     modules:
       - go.opentelemetry.io/otel/bridge/opencensus
       - go.opentelemetry.io/otel/bridge/opencensus/test
       - go.opentelemetry.io/otel/example/opencensus
       - go.opentelemetry.io/otel/example/prometheus
-      - go.opentelemetry.io/otel/example/view
-      - go.opentelemetry.io/otel/exporters/otlp/otlpmetric
       - go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc
       - go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp
       - go.opentelemetry.io/otel/exporters/prometheus