Fix synchronization object type in MultiTenantDbContext and update build task arguments

Author: Stephane Royer

src/.vscode/tasks.json

@@ -13,7 +13,8 @@
                 "build",
                 "${workspaceFolder}/Paillave.Etl.sln",
                 "/property:GenerateFullPaths=true",
-                "/consoleloggerparameters:NoSummary"
+                "/consoleloggerparameters:NoSummary",
+                "/p:WarningLevel=0",
             ],
             "problemMatcher": "$msCompile"
         },

src/Paillave.EntityFrameworkCoreExtension/Core/MultiTenantDbContext.cs

@@ -16,7 +16,7 @@ public interface ITenantProvider
 }
 public class MultiTenantDbContext(DbContextOptions options, ITenantProvider? tenantProvider = null) : DbContext(options)
 {
-    private readonly Lock _sync = new();
+    private readonly object _sync = new();
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
         modelBuilder.ApplyConfigurationsFromAssembly(this.GetType().Assembly);