compile time expressions everywhere

Author: Christoph Bergmeister

.azure-pipelines-ci/ci.yaml

@@ -44,7 +44,7 @@ stages:
               vmImage: windows-2019
               pwsh: false
         pool:
-          vmImage: $[ variables['vmImage'] ]
+          vmImage: ${{ variables['vmImage'] }}
         steps:
         - template: templates/test.yaml
           parameters:

.azure-pipelines-ci/templates/test.yaml

@@ -13,7 +13,7 @@ steps:
   displayName: 'Test'
   inputs:
     targetType: inline
-    pwsh: $[ parameters.pwsh ]
+    pwsh: ${{ parameters.pwsh }}
     script: |
       Import-Module .\tools\appveyor.psm1
       Invoke-AppveyorTest -CheckoutPath $env:BUILD_SOURCESDIRECTORY