Bump Microsoft.NET.Test.Sdk from 18.0.1 to 18.4.0

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Test/Test.csproj

@@ -9,7 +9,7 @@
     <PackageReference Include="log4net" Version="3.2.0" />
     <PackageReference Include="nunit" Version="4.4.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="6.0.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.4.0" />
     <PackageReference Include="SharpPcap" Version="6.3.1" />
   </ItemGroup>