Bump System.IO.Abstractions.TestingHelpers in /src

Bumps [System.IO.Abstractions.TestingHelpers](https://github.com/TestableIO/System.IO.Abstractions) from 21.0.29 to 21.1.3.
- [Release notes](https://github.com/TestableIO/System.IO.Abstractions/releases)
- [Commits](TestableIO/System.IO.Abstractions@v21.0.29...v21.1.3)

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

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

src/NVika.Tests/NVika.Tests.csproj

@@ -41,7 +41,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageReference Include="NSubstitute" Version="5.3.0" />
     <PackageReference Include="Serilog.Sinks.TextWriter" Version="3.0.0" />
-    <PackageReference Include="System.IO.Abstractions.TestingHelpers" Version="21.0.29" />
+    <PackageReference Include="System.IO.Abstractions.TestingHelpers" Version="21.1.3" />
     <PackageReference Include="xunit" Version="2.9.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
       <PrivateAssets>all</PrivateAssets>