GitHub Actions use win2019 & only push package on Windows

Author: devlead

.github/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest, ubuntu-latest, macos-latest]
+        os: [windows-2019, ubuntu-latest, macos-latest]
     steps:
       - name: Get the sources
         uses: actions/checkout@v2

build.cake

@@ -236,7 +236,10 @@ Task("Publish-NuGet")
 
 Task("Push-GitHub-Packages")
   .IsDependentOn("Package")
-    .WithCriteria(GitHubActions.IsRunningOnGitHubActions && !GitHubActions.Environment.PullRequest.IsPullRequest)
+    .WithCriteria(
+        GitHubActions.IsRunningOnGitHubActions &&
+        !GitHubActions.Environment.PullRequest.IsPullRequest &&
+        IsRunningOnWindows())
     .Does(() => {
 
       // Resolve the API key.