FS-11087: [Build-System] Use shared zlib library on Windows.

libs/win32/libpng/libpng.vcxproj

@@ -24,8 +24,8 @@
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>libpng</RootNamespace>
   </PropertyGroup>
-  <Import Project="$(ProjectDir)..\..\..\w32\zlib.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <Import Project="$(SolutionDir)w32\zlib.props" Condition=" '$(zlibImported)' == '' "/>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <CharacterSet>MultiByte</CharacterSet>