Reduce number of pushed duplicate packages (#8369)

The duplicate package push functional test pushes 160 packages in parallel. This is causing SQL timeouts. To unblock functional tests, we will temporarily reduce the number of duplicated packages we push to just 16. As part of #8368, we will improve the SQL query used to push packages and revert this change.

Part of #8368

tests/NuGetGallery.FunctionalTests/PackageCreation/ApiPushTests.cs

@@ -35,7 +35,9 @@ public async Task DuplicatePushesAreRejectedAndNotDeleted()
             // Arrange
             var packageId = $"{nameof(DuplicatePushesAreRejectedAndNotDeleted)}.{Guid.NewGuid():N}";
 
-            int pushVersionCount = 10;
+            // TODO: Increase this back to 10.
+            // See: https://github.com/NuGet/NuGetGallery/issues/8368
+            int pushVersionCount = 1;
             var duplicatePushTasks = new List<Task>();
             for (var duplicateTaskIndex = 0; duplicateTaskIndex < pushVersionCount; duplicateTaskIndex++)
             {