Update dependency Microsoft.Build to 17.12.6

Author: renovate-bot

Directory.Packages.props

@@ -40,7 +40,7 @@
     <PackageVersion Include="FluentFTP" Version="51.1.0" />
     <PackageVersion Include="Initialization.Microsoft.Extensions.DependencyInjection" Version="1.1.44" />
     <PackageVersion Include="MailKit" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.Build" Version="17.3.2" />
+    <PackageVersion Include="Microsoft.Build" Version="17.12.6" />
     <PackageVersion Include="Microsoft.CodeAnalysis" Version="4.1.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.11.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing.MSTest" Version="1.1.1" />