Add Directory.Build.props to solution items

This update includes Directory.Build.props in the solution, ensuring consistent build settings across the project. It helps centralize configuration and makes the build process more reliable.

Author: ivandrofly

SubDBSharp.sln

@@ -12,6 +12,7 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = ".Solution Items", ".Solution Items", "{6251D74E-7892-46E6-AF20-CF984220E79B}"
 	ProjectSection(SolutionItems) = preProject
 		Directory.Packages.props = Directory.Packages.props
+		Directory.Build.props = Directory.Build.props
 	EndProjectSection
 EndProject
 Global