remove unused import

Author: smaddock

src/Instrumentation/ReactPHP/src/ReactPHPInstrumentation.php

@@ -10,7 +10,6 @@
 use OpenTelemetry\API\Common\Time\ClockInterface;
 use OpenTelemetry\API\Globals;
 use OpenTelemetry\API\Instrumentation\CachedInstrumentation;
-use OpenTelemetry\API\Metrics\Noop\NoopHistogram;
 use OpenTelemetry\API\Trace\Span;
 use OpenTelemetry\API\Trace\SpanKind;
 use OpenTelemetry\API\Trace\StatusCode;