OCC-140: Fix dotnet package missing image. (#292)

* Add "Download NuGet icon" target.

* Add PackageIcon to all packaged projects.

* Include BeforeTargets="Pack".

* Don't try to push preview tags into NuGet.

* Detailed verbosity.

* Exclude preview from NuGet differently.

* Try BeforeTargets="Restore" instead.

* Copy local file instead, as download fails but only on GitHub runner.

* Revert "Detailed verbosity."

This reverts commit c0190ff.

* Not even Copy task works...

.github/workflows/publish-nuget.yml

@@ -7,6 +7,7 @@ on:
 
 jobs:
   call-publish-workflow:
+    if: contains(github.ref, 'preview') == false
     uses: Lombiq/GitHub-Actions/.github/workflows/publish-nuget.yml@dev
     secrets:
       API_KEY: ${{ secrets.NUGET_API_KEY }}

.gitignore

@@ -15,4 +15,3 @@ node_modules/
 *.placeholder
 /.editorconfig
 .ps1-analyzer-stamp
-OrchardCoreIcon.png

Directory.Build.props

@@ -11,13 +11,12 @@
     </PackageReference>
   </ItemGroup>
 
-  <!-- Copying the Lombiq logo as an icon to all NuGet-published projects. -->
-  <Target Name="Download NuGet icon"
+  <!-- Copying the Orchard logo as an icon to all NuGet-published projects. -->
+  <Target Name="Copy NuGet icon"
           AfterTargets="AfterResolveReferences"
           Condition="'$(PackageIcon)' == 'OrchardCoreIcon.png' AND !Exists('$(ProjectDir)OrchardCoreIcon.png')">
-    <DownloadFile
-      SourceUrl="https://api.nuget.org/v3-flatcontainer/orchardcore/1.5.0/icon"
-      DestinationFolder="$(ProjectDir)"
-      DestinationFileName="OrchardCoreIcon.png" />
+    <Copy SourceFiles="$(MSBuildThisFileDirectory)OrchardCoreIcon.png"
+          DestinationFiles="$(ProjectDir)OrchardCoreIcon.png"
+          SkipUnchangedFiles="true" />
   </Target>
 </Project>