Reuse ISessionFeature as we're testing its existence

Author: anna-git

tracer/src/Datadog.Trace/AppSec/Coordinator/SecurityCoordinatorHelpers.Core.cs

@@ -82,9 +82,9 @@ internal static void CheckPathParamsAndSessionId(this Security security, HttpCon
                 var args = new Dictionary<string, object> { { AddressesConstants.RequestPathParams, pathParams } };
                 IResult? result;
                 // we need to check context.Features.Get<ISessionFeature> as accessing the Session item if session has not been configured for the application is throwing InvalidOperationException
-                if (context.Features.Get<ISessionFeature>() is not null && (context.Session?.IsAvailable ?? false))
+                if (context.Features.Get<ISessionFeature>() is { } feature && (feature.Session?.IsAvailable ?? false))
                 {
-                    result = securityCoordinator.RunWaf(args, sessionId: context.Session.Id);
+                    result = securityCoordinator.RunWaf(args, sessionId: feature.Session.Id);
                 }
                 else
                 {