Metrics otlp exporter sample broken

[KieranP]

Description of the bug

Using metrics otlp exporter sample (https://github.com/open-telemetry/opentelemetry-ruby/blob/main/examples/metrics_sdk/metrics_collect_otlp.rb#L33) fails with:

undefined method `pull' for an instance of OpenTelemetry::SDK::Metrics::Export::PeriodicMetricReader

Share details about your runtime

Operating system details: Mac
RUBY_ENGINE: "ruby"
RUBY_VERSION: "3.3.6"
RUBY_DESCRIPTION: "ruby 3.3.6 (2024-11-05 revision 75015d4c1f) [arm64-darwin24]"

opentelemetry-api (1.4.0)
opentelemetry-common (0.21.0)
opentelemetry-exporter-otlp (0.29.1)
opentelemetry-exporter-otlp-metrics (0.3.0)
opentelemetry-metrics-api (0.2.0)
opentelemetry-metrics-sdk (0.5.0)
opentelemetry-registry (0.3.1)
opentelemetry-sdk (1.6.0)
opentelemetry-semantic_conventions (1.10.1)