Do not track methods if no parent activity is given.

backend/src/Squidex.Infrastructure/Telemetry.cs

@@ -17,16 +17,31 @@ namespace Squidex.Infrastructure
 
         public static Activity? StartMethod(this ActivitySource activity, Type type, [CallerMemberName] string? memberName = null)
         {
+            if (Activity.Current == null)
+            {
+                return null;
+            }
+
             return activity.StartActivity($"{type.Name}/{memberName}");
         }
 
         public static Activity? StartMethod<T>(this ActivitySource activity, [CallerMemberName] string? memberName = null)
         {
+            if (Activity.Current == null)
+            {
+                return null;
+            }
+
             return activity.StartActivity($"{typeof(T).Name}/{memberName}");
         }
 
         public static Activity? StartMethod(this ActivitySource activity, string objectName, [CallerMemberName] string? memberName = null)
         {
+            if (Activity.Current == null)
+            {
+                return null;
+            }
+
             return activity.StartActivity($"{objectName}/{memberName}");
         }
     }