Install Git for Windows with symbolic links enabled (actions#1186)

We only offer Windows environments that support symbolic links, meaning: if running either as administrator, or with Windows' Developer Mode enabled, symbolic links can be created.

However, Git for Windows' auto-detection assumes that if it is installed by an administrator, it cannot detect whether "regular" users can create symbolic links, and by way of playing it safe, disables symlink support.

Since we know better, we can avoid the auto-detection.

images/win/scripts/Installers/Install-Git.ps1

@@ -30,6 +30,7 @@ Install-Binary  -Url $downloadUrl `
                     "/RESTARTAPPLICATIONS", `
                     "/o:PathOption=CmdTools", `
                     "/o:BashTerminalOption=ConHost", `
+                    "/o:EnableSymlinks=Enabled", `
                     "/COMPONENTS=gitlfs")
 
 Choco-Install -PackageName hub