Remove JsonReader and JsonWriter - #124

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-dotnet@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Common/Encoders/LzString.cs(728,28): warning CS8603: Possible null reference return. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Common/LuYao.Common.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Common/Encoders/LzString.cs(74,16): warning CS8603: Possible null reference return. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Common/LuYao.Common.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/Net/Http/FakeUserAgent/BrowserItem.cs(60,19): warning CS8618: Non-nullable property 'Platform' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/LuYao.Net.Http.FakeUserAgent.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/Net/Http/FakeUserAgent/BrowserItem.cs(55,19): warning CS8618: Non-nullable property 'OSVersion' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/LuYao.Net.Http.FakeUserAgent.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/Net/Http/FakeUserAgent/BrowserItem.cs(50,19): warning CS8618: Non-nullable property 'OS' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/LuYao.Net.Http.FakeUserAgent.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/Net/Http/FakeUserAgent/BrowserItem.cs(45,19): warning CS8618: Non-nullable property 'BrowserVersion' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/LuYao.Net.Http.FakeUserAgent.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/Net/Http/FakeUserAgent/BrowserItem.cs(40,19): warning CS8618: Non-nullable property 'Browser' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/LuYao.Net.Http.FakeUserAgent.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/Net/Http/FakeUserAgent/BrowserItem.cs(35,19): warning CS8618: Non-nullable property 'DeviceBrand' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/LuYao.Net.Http.FakeUserAgent.csproj::TargetFramework=net45]

/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/Net/Http/FakeUserAgent/BrowserItem.cs(30,19): warning CS8618: Non-nullable property 'Type' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable. [/home/runner/work/luyao-dotnet/luyao-dotnet/src/LuYao.Net.Http.FakeUserAgent/LuYao.Net.Http.FakeUserAgent.csproj::TargetFramework=net45]