Bump System.Text.Json from 8.0.5 to 9.0.0 in /src (#561)

Bumps [System.Text.Json](https://github.com/dotnet/runtime) from 8.0.5 to 9.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v8.0.5...v9.0.0)

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

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

Author: dependabot[bot]

src/Directory.Packages.props

@@ -25,7 +25,7 @@
     <PackageVersion Include="System.Management" Version="9.0.0" />
     <PackageVersion Include="System.Net.Http" Version="4.3.4" />
     <PackageVersion Include="System.Runtime.InteropServices.RuntimeInformation" Version="4.3.0" />
-    <PackageVersion Include="System.Text.Json" Version="8.0.5" />
+    <PackageVersion Include="System.Text.Json" Version="9.0.0" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />
     <PackageVersion Include="Verify.ImageMagick" Version="3.6.0" />
     <PackageVersion Include="Verify.WinForms" Version="4.0.0" />