Update Directory.Build.targets

Author: jmcouffin

dev/Directory.Build.targets

@@ -20,7 +20,7 @@
         <PyRevitExtDir>$(PyRevitRootDir)\extensions</PyRevitExtDir>
 
         <RevitDevDir>$(PyRevitDevDir)\libs\Revit</RevitDevDir>
-        <IronPythonStdLibDir>$(PyRevitDevDir)\libs\IronPython\</IronPythonStdLibDir>
+        <IronPythonStdLibDir>$(PyRevitDevDir)\libs\IronPython</IronPythonStdLibDir>
     </PropertyGroup>
 
     <PropertyGroup Condition="$(UseDefaultBin) == 'true'">
@@ -31,4 +31,4 @@
         <RevitVersion Condition="'$(RevitVersion)' == '' and '$(TargetFramework)' == 'net48'">2017</RevitVersion>
         <RevitVersion Condition="'$(RevitVersion)' == '' and '$(TargetFramework)' == 'net8.0-windows'">2025</RevitVersion>
     </PropertyGroup>
-</Project>
+</Project>