GitHub Actions: Use preinstalled dependencies on Windows

The Windows image provided by GitHub already includes most of our dependencies,
so the installation of all Chocolatey packages except winflexbison3 was
redundant. Visual Studio is provided in the Enterprise version instead of
Community, so that has to be added to the search path as well.

doc/win-dev.ps1

@@ -70,43 +70,26 @@ try {
 	$Env:Path += $ChocoPath
 }
 
-
-choco install -y "visualstudio${VsVersion}community"
-ThrowOnNativeFailure
-
-choco install -y "visualstudio${VsVersion}-workload-netcoretools"
-ThrowOnNativeFailure
-
-choco install -y "visualstudio${VsVersion}-workload-vctools"
-ThrowOnNativeFailure
-
-choco install -y "visualstudio${VsVersion}-workload-manageddesktop"
-ThrowOnNativeFailure
-
-choco install -y "visualstudio${VsVersion}-workload-nativedesktop"
-ThrowOnNativeFailure
-
-choco install -y "visualstudio${VsVersion}-workload-universal"
-ThrowOnNativeFailure
-
-choco install -y "visualstudio${VsVersion}buildtools"
-ThrowOnNativeFailure
-
-
-choco install -y git
-ThrowOnNativeFailure
-
-choco install -y cmake
-ThrowOnNativeFailure
-
-choco install -y winflexbison3
-ThrowOnNativeFailure
-
-choco install -y windows-sdk-8.1
-ThrowOnNativeFailure
-
-choco install -y wixtoolset
-ThrowOnNativeFailure
+# GitHub Actions uses an image that comes with most dependencies preinstalled. Don't install them twice.
+if (-not $Env:GITHUB_ACTIONS) {
+    choco install -y `
+        "visualstudio${VsVersion}community" `
+        "visualstudio${VsVersion}-workload-netcoretools" `
+        "visualstudio${VsVersion}-workload-vctools" `
+        "visualstudio${VsVersion}-workload-manageddesktop" `
+        "visualstudio${VsVersion}-workload-nativedesktop" `
+        "visualstudio${VsVersion}-workload-universal" `
+        "visualstudio${VsVersion}buildtools" `
+        git `
+        cmake `
+        winflexbison3 `
+        windows-sdk-8.1 `
+        wixtoolset
+    ThrowOnNativeFailure
+} else {
+    choco install -y winflexbison3
+    ThrowOnNativeFailure
+}
 
 
 Install-Exe -Url "https://packages.icinga.com/windows/dependencies/boost_$($BoostVersion -join '_')-msvc-${MsvcVersion}-${Env:BITS}.exe" -Dir "C:\local\boost_$($BoostVersion -join '_')-Win${Env:BITS}"

tools/win32/load-vsenv.ps1

@@ -29,8 +29,9 @@ if (Test-Path env:BITS) {
 
 # Execute vcvars in cmd and store env
 $vcvars_locations = @(
-  "${VSBASE}\BuildTools\VC\Auxiliary\Build\vcvars${bits}.bat",
+  "${VSBASE}\BuildTools\VC\Auxiliary\Build\vcvars${bits}.bat"
   "${VSBASE}\Community\VC\Auxiliary\Build\vcvars${bits}.bat"
+  "${VSBASE}\Enterprise\VC\Auxiliary\Build\vcvars${bits}.bat"
 )
 
 $vcvars = $null