Bump System.IO.Ports from 5.0.1 to 6.0.0

Bumps [System.IO.Ports](https://github.com/dotnet/runtime) from 5.0.1 to 6.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v5.0.1...v6.0.0)

---
updated-dependencies:
- dependency-name: System.IO.Ports
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

SerialPortRx/SerialPortRx.csproj

@@ -3,7 +3,7 @@
   <ItemGroup>
     <Compile Update="**\*.cs" DependentUpon="I%(Filename).cs" />
     <PackageReference Include="System.Reactive" Version="5.0.0" />
-    <PackageReference Include="System.IO.Ports" Version="5.0.1" />
+    <PackageReference Include="System.IO.Ports" Version="6.0.0" />
   </ItemGroup>
 
 </Project>