chore(deps): update dependency markdig to 0.43.0

Author: renovate[bot]

Directory.Packages.props

@@ -27,7 +27,7 @@
 
     <!-- Code quality -->
     <PackageVersion Include="FluentValidation" Version="12.0.0" />
-    <PackageVersion Include="Markdig" Version="0.41.3" />
+    <PackageVersion Include="Markdig" Version="0.43.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Http" Version="2.3.0" />
 
     <!-- Versioning -->