fix(): otlp exporter

Author: sandy2008

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OtlpExporterOptions.cs

@@ -179,7 +179,6 @@ public Func<HttpClient> HttpClientFactory
     /// </summary>
     public string ClientCertificateFile { get; set; }
 
-#if NET6_0_OR_GREATER
     /// <summary>
     /// Gets a value indicating whether or not the signal-specific path should
     /// be appended to <see cref="Endpoint"/>.