Bump TUnit from 1.3.15 to 1.5.6 (#409)

---
updated-dependencies:
- dependency-name: TUnit
  dependency-version: 1.5.6
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Directory.Packages.props

@@ -22,7 +22,7 @@
     <PackageVersion Include="NUnit" Version="4.4.0" />
     <PackageVersion Include="NUnit3TestAdapter" Version="6.0.0" />
     <PackageVersion Include="System.Formats.Asn1" Version="9.0.10" />
-    <PackageVersion Include="TUnit" Version="1.3.15" />
+    <PackageVersion Include="TUnit" Version="1.5.6" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
     <PackageVersion Include="xunit.v3" Version="3.2.1" />
   </ItemGroup>