[ASP.NET Core] Remove suppression for metrics generated from promethe…

…us (#5044)

src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md

@@ -35,6 +35,12 @@ exception. The attribute value will be set to full name of exception type.
 * Fixed `network.protocol.version` attribute values to match the specification.
   ([#5007](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5007))
 
+* Calls to `/metrics` will now be included in the `http.server.request.duration`
+  metric. This change may affect Prometheus pull scenario if the Prometheus
+  server sends request to the scraping endpoint that contains `/metrics` in
+  path.
+  ([#5044](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5044))
+
 ## 1.6.0-beta.2
 
 Released 2023-Oct-26

src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInMetricsListener.cs

@@ -185,14 +185,6 @@ public void OnEventWritten_New(string name, object payload)
             return;
         }
 
-        // TODO: Prometheus pulls metrics by invoking the /metrics endpoint. Decide if it makes sense to suppress this.
-        // Below is just a temporary way of achieving this suppression for metrics (we should consider suppressing traces too).
-        // If we want to suppress activity from Prometheus then we should use SuppressInstrumentationScope.
-        if (context.Request.Path.HasValue && context.Request.Path.Value.Contains("metrics"))
-        {
-            return;
-        }
-
         TagList tags = default;
 
         // see the spec https://github.com/open-telemetry/semantic-conventions/blob/v1.21.0/docs/http/http-spans.md