Bump System.IO.Packaging from 6.0.0 to 8.0.0

Bumps [System.IO.Packaging](https://github.com/dotnet/runtime) from 6.0.0 to 8.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v6.0.0...v8.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

src/Directory.Packages.props

@@ -12,7 +12,7 @@
     <PackageVersion Include="Microsoft.AnalysisServices.AdomdClient.NetCore.retail.amd64" Version="$(MicrosoftAnalysisServicesVersion)" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="1.1.1" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
-    <PackageVersion Include="System.IO.Packaging" Version="6.0.0" />
+    <PackageVersion Include="System.IO.Packaging" Version="8.0.0" />
     <PackageVersion Include="coverlet.collector" Version="6.0.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
     <PackageVersion Include="xunit" Version="2.6.6" />