make CultureContext treadsafe

Author: 6bee

test/Remote.Linq.Tests/TestHelper.cs

@@ -10,6 +10,7 @@ namespace Remote.Linq.Tests;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using Xunit.Sdk;
 using MethodInfo = System.Reflection.MethodInfo;
@@ -84,17 +85,20 @@ public static bool IsCollection(this Type type)
 
     private sealed class CultureContext : IDisposable
     {
+        private static readonly SemaphoreSlim _semaphore = new(1, 1);
         private readonly CultureInfo _culture;
 
         public CultureContext(CultureInfo culture)
         {
+            _semaphore.Wait();
             _culture = CultureInfo.CurrentCulture;
             CultureInfo.CurrentCulture = culture;
         }
 
         public void Dispose()
         {
             CultureInfo.CurrentCulture = _culture;
+            _semaphore.Release();
         }
     }