V16: Allow MaxRequestLength to be specified as a long (#18141)

* feat: allows MaxFileSize to be specified as 64-bit rather than 32-bit to be able to accept larger files

the underlying kestrel architecture already accepts a `long` in ConfigureKestrelServerOptions.cs

* chore: removes unused configuration option

* chore: generate OpenApi.json

src/Umbraco.Core/Configuration/Models/RuntimeSettings.cs

@@ -18,15 +18,10 @@ public class RuntimeSettings
     [DefaultValue(RuntimeMode.BackofficeDevelopment)]
     public RuntimeMode Mode { get; set; } = RuntimeMode.BackofficeDevelopment;
 
-    /// <summary>
-    /// Gets or sets a value for the maximum query string length.
-    /// </summary>
-    public int? MaxQueryStringLength { get; set; }
-
     /// <summary>
     ///     Gets or sets a value for the maximum request length in kb.
     /// </summary>
-    public int? MaxRequestLength { get; set; }
+    public long? MaxRequestLength { get; set; }
 
     /// <summary>
     /// Gets or sets the timespan temporary files are kept, before they are removed by a background task.