Bump System.Text.Json from 5.0.0 to 8.0.4 in /Gw2Sharp

Bumps System.Text.Json from 5.0.0 to 8.0.4.

---
updated-dependencies:
- dependency-name: System.Text.Json
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Gw2Sharp/Gw2Sharp.csproj

@@ -36,11 +36,11 @@ Check the changelog at https://github.com/Archomeda/Gw2Sharp/blob/master/CHANGEL
   <ItemGroup Condition="'$(TargetFramework)'=='netstandard2.0'">
     <PackageReference Include="TunnelVisionLabs.ReferenceAssemblyAnnotator" Version="1.0.0-alpha.154" PrivateAssets="all" />
     <PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[3.1.0]" />
-    <PackageReference Include="System.Text.Json" Version="5.0.0" />
+    <PackageReference Include="System.Text.Json" Version="8.0.4" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)'=='netcoreapp3.1'">
-    <PackageReference Include="System.Text.Json" Version="5.0.0" />
+    <PackageReference Include="System.Text.Json" Version="8.0.4" />
   </ItemGroup>
 
   <PropertyGroup Condition="'$(VERSIONED_BUILD)'!=''">