fix: sort imports in ExportTest to satisfy spotless

Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: zeitlinger

prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/ExportTest.java

@@ -8,9 +8,9 @@
 import io.opentelemetry.sdk.metrics.data.MetricData;
 import io.opentelemetry.sdk.metrics.export.MetricReader;
 import io.opentelemetry.sdk.resources.Resource;
-import io.opentelemetry.sdk.testing.exporter.InMemoryMetricReader;
 import io.opentelemetry.sdk.testing.assertj.MetricAssert;
 import io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions;
+import io.opentelemetry.sdk.testing.exporter.InMemoryMetricReader;
 import io.opentelemetry.sdk.testing.junit5.OpenTelemetryExtension;
 import io.prometheus.metrics.core.metrics.Counter;
 import io.prometheus.metrics.core.metrics.Gauge;