hard code 6.0.36 as it's going out of support after that

Author: marcpopMSFT

eng/Versions.props

@@ -34,7 +34,7 @@
     <VersionFeature21>30</VersionFeature21>
     <VersionFeature31>32</VersionFeature31>
     <VersionFeature50>17</VersionFeature50>
-    <VersionFeature60>$([MSBuild]::Add($(VersionFeature), 36))</VersionFeature60>
+    <VersionFeature60>36</VersionFeature60>
     <VersionFeature70>20</VersionFeature70>
     <VersionFeature80>$([MSBuild]::Add($(VersionFeature), 11))</VersionFeature80>
     <!-- Should be kept in sync with VersionFeature70. It should match the version of Microsoft.NET.ILLink.Tasks