build(deps): bump System.Text.Json from 7.0.3 to 8.0.0 (#1613)

Bumps [System.Text.Json](https://github.com/dotnet/runtime) from 7.0.3 to 8.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v7.0.3...v8.0.0)

---
updated-dependencies:
- dependency-name: System.Text.Json
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Refit/Refit.csproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Text.Json" Version="7.0.3" />
+    <PackageReference Include="System.Text.Json" Version="8.0.0" />
     <PackageReference Include="System.Net.Http.Json" Version="7.0.1" />
   </ItemGroup>