nuget-deps: bump System.Text.Json from 5.0.2 to 6.0.2 in /src/Notepads

Bumps [System.Text.Json](https://github.com/dotnet/runtime) from 5.0.2 to 6.0.2.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v5.0.2...v6.0.2)

---
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>

src/Notepads/Notepads.csproj

@@ -434,7 +434,7 @@
       <Version>13.0.1</Version>
     </PackageReference>
     <PackageReference Include="System.Text.Json">
-      <Version>5.0.2</Version>
+      <Version>6.0.2</Version>
     </PackageReference>
     <PackageReference Include="UTF.Unknown">
       <Version>2.5.0</Version>