Remove dependency on System.Text.Json.

Author: mo-esmp

src/Serilog.Ui.MongoDbServerProvider/Serilog.Ui.MongoDbServerProvider.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
@@ -7,7 +7,7 @@
   <ItemGroup>
     <PackageReference Include="MongoDB.Bson" Version="2.11.5" />
     <PackageReference Include="MongoDB.Driver" Version="2.11.5" />
-    <PackageReference Include="System.Text.Json" Version="5.0.0" />
+    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
   </ItemGroup>
 
   <ItemGroup>