Improve task scheduling and code quality

- Simplified `SuppressMessage` attributes in `BasicTests.cs`
  and `BufferingChannelReader.cs` for cleaner metadata.
- Updated `Task.ContinueWith` in `Extensions._.cs` to use
  `TaskContinuationOptions.ExecuteSynchronously` and
  `TaskScheduler.Current` for better performance.
- Incremented project version to 9.1.1 in `Open.ChannelExtensions.csproj`.
- Introduced conditional compilation for `SyncLock` in
  `BufferingChannelReader.cs` to support .NET 9.0+ features.
- Removed unnecessary global `SuppressMessage` in `_Global.cs`
  after addressing the underlying issue.

Author: electricessence

Open.ChannelExtensions.Tests/BasicTests.cs

@@ -9,7 +9,7 @@ public static class BasicTests
 	[InlineData(testSize1)]
 	[InlineData(testSize2)]
 	[SuppressMessage("Reliability", "CA2012:Use ValueTasks correctly", Justification = "Testing only.")]
-	[SuppressMessage("CodeQuality", "IDE0079:Remove unnecessary suppression", Justification = "<Pending>")]
+	[SuppressMessage("CodeQuality", "IDE0079:Remove unnecessary suppression")]
 	public static async Task DeferredWriteRead(int testSize)
 	{
 		IEnumerable<int> range = Enumerable.Range(0, testSize);

Open.ChannelExtensions/Extensions._.cs

@@ -109,7 +109,7 @@ public static ChannelReader<TSource> PropagateCompletion<TSource, TTarget>(
 				target.TryComplete(t.Exception);
 			else
 				target.TryComplete();
-		}, cancellationToken);
+		}, cancellationToken, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Current);
 
 		return source;
 	}

Open.ChannelExtensions/Open.ChannelExtensions.csproj

@@ -22,7 +22,7 @@
 		<RepositoryType>git</RepositoryType>
 		<GeneratePackageOnBuild>true</GeneratePackageOnBuild>
 		<GenerateDocumentationFile>true</GenerateDocumentationFile>
-		<Version>9.1.0</Version>
+		<Version>9.1.1</Version>
 		<PackageReleaseNotes>Ensure the current task scheduler is used and that it can be configured.</PackageReleaseNotes>
 		<PackageLicenseExpression>MIT</PackageLicenseExpression>
 		<PublishRepositoryUrl>true</PublishRepositoryUrl>

Open.ChannelExtensions/Readers/BufferingChannelReader.cs

@@ -20,7 +20,7 @@ public abstract class BufferingChannelReader<TIn, TOut> : ChannelReader<TOut>
 	/// <summary>
 	/// The synchronization lock for the buffer.
 	/// </summary>
-	[SuppressMessage("Design", "CA1051:Do not declare visible instance fields", Justification = "<Pending>")]
+	[SuppressMessage("Design", "CA1051:Do not declare visible instance fields")]
 #if NET9_0_OR_GREATER
 	protected readonly System.Threading.Lock SyncLock = new();
 #else

Open.ChannelExtensions/_Global.cs

@@ -8,5 +8,3 @@
 global using System.Threading;
 global using System.Threading.Channels;
 global using System.Threading.Tasks;
-
-[assembly: SuppressMessage("Reliability", "CA2008:Do not create tasks without passing a TaskScheduler", Justification = "<Pending>", Scope = "member", Target = "~M:Open.ChannelExtensions.Extensions.PropagateCompletion``2(System.Threading.Channels.ChannelReader{``0},System.Threading.Channels.ChannelWriter{``1},System.Threading.CancellationToken)~System.Threading.Channels.ChannelReader{``0}")]