MetricReader gives transient, incorrect warnings

The MetricReader gives this warning in stdout:

WARNING:opentelemetry.sdk.metrics._internal.export:Cannot call collect on a MetricReader until it is registered on a MeterProvider
WARNING:opentelemetry.sdk.metrics._internal.export:Cannot call collect on a MetricReader until it is registered on a MeterProvider

However, the MetricReader is indeed registered with a MeterProvider:

OTLP_ENDPOINT=os.getenv("OTLP_ENDPOINT")
otlp_metric_reader = PeriodicExportingMetricReader(OTLPMetricExporter(endpoint=OTLP_ENDPOINT))
mprovider = MeterProvider(resource=resource, metric_readers=[otlp_metric_reader])
metrics.set_meter_provider(mprovider)
meter = metrics.get_meter("demo-meter")

latency_histogram = meter.create_histogram(
    "response_time",
    unit="ms",
    description="Time spent in a request",
)
call_count = meter.create_counter(
    "call_count",
    unit="1",
    description="Number of requests",
)

... # see https://github.com/open-telemetry/opentelemetry-python-contrib/issues/2075 for full setup

Start with the MetricReader and MeterProvider setup shown in the issue, then compare it with issue #2075's full setup. Reproduce the two warnings and trace when collection occurs relative to registration. Done means valid registration no longer emits the reported transient warnings, with coverage for the reported setup.