build(deps): bump System.IO.Abstractions from 20.0.15 to 21.0.2

Bumps [System.IO.Abstractions](https://github.com/TestableIO/System.IO.Abstractions) from 20.0.15 to 21.0.2.
- [Release notes](https://github.com/TestableIO/System.IO.Abstractions/releases)
- [Commits](TestableIO/System.IO.Abstractions@v20.0.15...v21.0.2)

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

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

Directory.Packages.props

@@ -15,7 +15,7 @@
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.5.7" />
     <PackageVersion Include="coverlet.collector" Version="6.0.2" />
     <PackageVersion Include="System.CommandLine" Version="2.0.0-beta4.22272.1" />
-    <PackageVersion Include="System.IO.Abstractions" Version="20.0.15" />
+    <PackageVersion Include="System.IO.Abstractions" Version="21.0.2" />
     <PackageVersion Include="System.IO.Abstractions.TestingHelpers" Version="21.0.2" />
   </ItemGroup>
 </Project>