[build] Remove explicit snupkg pushing

*.snupkg files are pushed together with corresponding *.nupkg

.github/workflows/publish-nightly.yaml

@@ -25,7 +25,3 @@ jobs:
         env:
           MYGET_API_KEY: ${{ secrets.MYGET_API_KEY }}
         run: ./.dotnet/dotnet nuget push **/*.nupkg --source https://www.myget.org/F/benchmarkdotnet/api/v3/index.json --api-key $MYGET_API_KEY --timeout 600
-      - name: Publish snupkg
-        env:
-          MYGET_API_KEY: ${{ secrets.MYGET_API_KEY }}
-        run: ./.dotnet/dotnet nuget push **/*.snupkg --source https://www.myget.org/F/benchmarkdotnet/api/v3/index.json --api-key $MYGET_API_KEY --timeout 600

build/BenchmarkDotNet.Build/Runners/ReleaseRunner.cs

@@ -101,7 +101,7 @@ public class ReleaseRunner
         var nuGetToken = EnvVar.NuGetToken.GetValue();
 
         var files = context
-            .GetFiles(context.ArtifactsDirectory.CombineWithFilePath("*").FullPath)
+            .GetFiles(context.ArtifactsDirectory.CombineWithFilePath("*.nupkg").FullPath)
             .OrderBy(file => file.FullPath);
         var settings = new DotNetNuGetPushSettings
         {