Fix System.Text.Json vulnerability warning (grpc#2556)

Author: JamesNK

Directory.Packages.props

@@ -82,6 +82,7 @@
     <PackageVersion Include="System.Memory" Version="4.5.3" />
     <PackageVersion Include="System.Net.Http.WinHttpHandler" Version="8.0.0" />
     <PackageVersion Include="System.Security.Principal.Windows" Version="5.0.0" />
+    <PackageVersion Include="System.Text.Json" Version="6.0.10" />
     <PackageVersion Include="System.Threading.Channels" Version="4.6.0" />
   </ItemGroup>
 </Project>

src/dotnet-grpc/dotnet-grpc.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <Description>Command line tool for gRPC projects</Description>
     <PackageTags>gRPC RPC CLI</PackageTags>
@@ -26,6 +26,7 @@
     <PackageReference Include="Microsoft.Build.Locator" />
     <PackageReference Include="System.CommandLine.Rendering" />
     <PackageReference Include="System.Security.Principal.Windows" />
+    <PackageReference Include="System.Text.Json" />
     <PackageReference Include="Microsoft.Win32.Registry" />
   </ItemGroup>