Remove the unused Resource field from the MeterProvider (#3253)

sdk/metric/provider.go

@@ -19,16 +19,13 @@ import (
 
 	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
-	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // MeterProvider handles the creation and coordination of Meters. All Meters
 // created by a MeterProvider will be associated with the same Resource, have
 // the same Views applied to them, and have their produced metric telemetry
 // passed to the configured Readers.
 type MeterProvider struct {
-	res *resource.Resource
-
 	meters meterRegistry
 
 	forceFlush, shutdown func(context.Context) error
@@ -51,8 +48,6 @@ func NewMeterProvider(options ...Option) *MeterProvider {
 	registry := newPipelines(conf.res, conf.readers)
 
 	return &MeterProvider{
-		res: conf.res,
-
 		meters: meterRegistry{
 			pipes: registry,
 		},