build(deps): Bump AutoFixture from 4.17.0 to 4.18.0

Bumps [AutoFixture](https://github.com/AutoFixture/AutoFixture) from 4.17.0 to 4.18.0.
- [Release notes](https://github.com/AutoFixture/AutoFixture/releases)
- [Commits](AutoFixture/AutoFixture@v4.17.0...v4.18.0)

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

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

Author: dependabot[bot]

tests/Directory.Build.props

@@ -15,7 +15,7 @@
 	</PropertyGroup>
 
 	<ItemGroup Condition="$(MSBuildProjectName) != 'bunit.testassets'">
-		<PackageReference Include="AutoFixture" Version="4.17.0" />
+		<PackageReference Include="AutoFixture" Version="4.18.0" />
 		<PackageReference Include="AutoFixture.Xunit2" Version="4.17.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.1" />
     <PackageReference Include="Moq" Version="4.18.4" />