No need to check for errors in golang example

[LordRahl90]

The provider creation does not return error. So no need to check the errors after creating the providers.

This subsequently means there's no need to handle errors within the function.

[CLAassistant]

All committers have signed the CLA.

[zeitlinger]

thanks for the contribution

we try to keep this code in sync with https://github.com/open-telemetry/opentelemetry-go/blob/main/example/dice/otel.go - so it's probably best to suggest the simplification there