Make progress events serial

Author: david-driscoll

src/Dap.Protocol/Feature/Events/ProgressFeature.cs

@@ -23,7 +23,7 @@ public abstract record ProgressEvent
             public string? Message { get; init; }
         }
 
-        [Parallel]
+        [Serial]
         [Method(EventNames.ProgressStart, Direction.ServerToClient)]
         [
             GenerateHandler,
@@ -60,7 +60,7 @@ public record ProgressStartEvent : ProgressEvent, IRequest
             public int? Percentage { get; init; }
         }
 
-        [Parallel]
+        [Serial]
         [Method(EventNames.ProgressUpdate, Direction.ServerToClient)]
         [
             GenerateHandler,
@@ -76,7 +76,7 @@ public record ProgressUpdateEvent : ProgressEvent, IRequest
             public double? Percentage { get; init; }
         }
 
-        [Parallel]
+        [Serial]
         [Method(EventNames.ProgressEnd, Direction.ServerToClient)]
         [
             GenerateHandler,

src/Protocol/Features/ProgressFeature.cs

@@ -19,7 +19,7 @@ namespace OmniSharp.Extensions.LanguageServer.Protocol
 {
     namespace Models
     {
-        [Parallel]
+        [Serial]
         [Method(GeneralNames.Progress, Direction.Bidirectional)]
         [GenerateHandler("OmniSharp.Extensions.LanguageServer.Protocol"), GenerateHandlerMethods,
          GenerateRequestMethods(typeof(IGeneralLanguageClient), typeof(ILanguageClient), typeof(IGeneralLanguageServer), typeof(ILanguageServer))]