Make sure the feed url is available to msbuild

We use this in some projects to autoomatically check for updates from a dotnet tool, for example. This relies on knowing which feed to check for updates, and variables aren't automatically made visible to the steps.

Author: kzu

.github/workflows/build.yml

@@ -28,6 +28,7 @@ env:
   GH_TOKEN: ${{ secrets.GH_TOKEN }}
   MSBUILDTERMINALLOGGER: auto
   Configuration: ${{ github.event.inputs.configuration || 'Release' }}
+  SLEET_FEED_URL: ${{ vars.SLEET_FEED_URL }}
 
 defaults:
   run:

.github/workflows/publish.yml

@@ -15,7 +15,8 @@ env:
   VersionLabel: ${{ github.ref }}
   GH_TOKEN: ${{ secrets.GH_TOKEN }}
   MSBUILDTERMINALLOGGER: auto
-    
+  SLEET_FEED_URL: ${{ vars.SLEET_FEED_URL }}
+      
 jobs:
   publish:
     runs-on: ${{ vars.PUBLISH_AGENT || 'ubuntu-latest' }}