Remove Windows-only skip from CRLF read acceptance tests

TextReader.ReadLineAsync handles \r\n on all platforms, so there's
no reason to restrict these tests to Windows.

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>

Author: Copilot

tests/ModelContextProtocol.Tests/Transport/StdioClientTransportTests.cs

@@ -11,7 +11,6 @@ namespace ModelContextProtocol.Tests.Transport;
 public class StdioClientTransportTests(ITestOutputHelper testOutputHelper) : LoggedTest(testOutputHelper)
 {
     public static bool IsStdErrCallbackSupported => !PlatformDetection.IsMonoRuntime;
-    public static bool IsWindows => PlatformDetection.IsWindows;
 
     [Fact]
     public async Task CreateAsync_ValidProcessInvalidServer_Throws()
@@ -166,7 +165,7 @@ public async Task SendMessageAsync_Should_Use_LF_Not_CRLF()
         Assert.Equal(expected, json);
     }
 
-    [Fact(Skip = "Non-Windows platform", SkipUnless = nameof(IsWindows))]
+    [Fact]
     public async Task ReadMessagesAsync_Should_Accept_CRLF_Delimited_Messages()
     {
         Pipe serverInputPipe = new();

tests/ModelContextProtocol.Tests/Transport/StdioServerTransportTests.cs

@@ -11,8 +11,6 @@ namespace ModelContextProtocol.Tests.Transport;
 
 public class StdioServerTransportTests : LoggedTest
 {
-    public static bool IsWindows => PlatformDetection.IsWindows;
-
     private readonly McpServerOptions _serverOptions;
 
     public StdioServerTransportTests(ITestOutputHelper testOutputHelper)
@@ -251,7 +249,7 @@ public async Task SendMessageAsync_Should_Use_LF_Not_CRLF()
         Assert.NotEqual((byte)'\r', bytes[^2]);
     }
 
-    [Fact(Skip = "Non-Windows platform", SkipUnless = nameof(IsWindows))]
+    [Fact]
     public async Task ReadMessagesAsync_Should_Accept_CRLF_Delimited_Messages()
     {
         var message = new JsonRpcRequest { Method = "test", Id = new RequestId(44) };