Add OpenTelemetry Support for `smallrye-reactive-messaging-gcp-pubsub`

[raphasil]

Currently, smallrye-reactive-messaging-gcp-pubsub does not have built-in support for OpenTelemetry, making it difficult to trace Pub/Sub messages effectively. Adding OpenTelemetry instrumentation would improve observability for applications using this connector.

Proposed Solution:

• Integrate OpenTelemetry support into smallrye-reactive-messaging-gcp-pubsub to enable tracing for both published and consumed messages.
• Provide a way to enable/disable tracing via configuration.
• Upgrade com.google.cloud dependency to 26.55.0

Reference:
https://cloud.google.com/pubsub/docs/open-telemetry-tracing

[raphasil]

Is there any update here? Am I missing anything?