Bump io.opentelemetry.instrumentation:opentelemetry-grpc-1.6

Bumps [io.opentelemetry.instrumentation:opentelemetry-grpc-1.6](https://github.com/open-telemetry/opentelemetry-java-instrumentation) from 2.16.0-alpha to 2.18.1-alpha.
- [Release notes](https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases)
- [Changelog](https://github.com/open-telemetry/opentelemetry-java-instrumentation/blob/main/CHANGELOG.md)
- [Commits](https://github.com/open-telemetry/opentelemetry-java-instrumentation/commits)

---
updated-dependencies:
- dependency-name: io.opentelemetry.instrumentation:opentelemetry-grpc-1.6
  dependency-version: 2.18.1-alpha
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

fabric-chaincode-shim/build.gradle

@@ -60,7 +60,7 @@ dependencies {
     implementation 'io.opentelemetry:opentelemetry-exporter-otlp'
     implementation 'io.opentelemetry:opentelemetry-extension-trace-propagators'
     implementation 'io.opentelemetry.semconv:opentelemetry-semconv:1.32.0'
-    implementation 'io.opentelemetry.instrumentation:opentelemetry-grpc-1.6:2.16.0-alpha'
+    implementation 'io.opentelemetry.instrumentation:opentelemetry-grpc-1.6:2.18.1-alpha'
 }
 
 sourceSets {