[exporter/stefexporter] Update STEF dependency to v0.0.3 (#37916)

#### Description

Updated STEF dependency from v0.0.2 to v0.0.3 and made a corresponding
minor change due to breaking changes in STEF API.

I assume no changelog is need but let me know if you think otherwise.

exporter/stefexporter/exporter.go

@@ -191,7 +191,7 @@ func (s *stefExporter) exportMetrics(ctx context.Context, md pmetric.Metrics) er
 	s.stefWriterMutex.Lock()
 	defer s.stefWriterMutex.Unlock()
 
-	converter := stefpdatametrics.OtlpToTEFUnsorted{}
+	converter := stefpdatametrics.OtlpToSTEFUnsorted{}
 	err := converter.WriteMetrics(md, s.stefWriter)
 	if err != nil {
 		// Error to write to STEF stream typically indicates either:

exporter/stefexporter/go.mod

@@ -4,10 +4,10 @@ go 1.23.0
 
 require (
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/common v0.119.1-0.20250210123122-44b3eeda354c
-	github.com/splunk/stef/go/grpc v0.0.2
-	github.com/splunk/stef/go/otel v0.0.2
-	github.com/splunk/stef/go/pdata v0.0.2
-	github.com/splunk/stef/go/pkg v0.0.2
+	github.com/splunk/stef/go/grpc v0.0.3
+	github.com/splunk/stef/go/otel v0.0.3
+	github.com/splunk/stef/go/pdata v0.0.3
+	github.com/splunk/stef/go/pkg v0.0.3
 	github.com/stretchr/testify v1.10.0
 	go.opentelemetry.io/collector/component v0.119.1-0.20250210123122-44b3eeda354c
 	go.opentelemetry.io/collector/component/componenttest v0.119.1-0.20250210123122-44b3eeda354c