Revert "fix: handling of empty packages sequence"

This reverts commit 8b6cf7e.

src/CTA.Rules.ProjectFile/ProjectFileCreator.cs

@@ -295,15 +295,11 @@ private void UpdatePackageReferences()
                 .GroupBy(d => d.Name).Select(d => d.FirstOrDefault())
                 .ToDictionary(p => p.Name, p => p.Version);
 
-            // if packages is empty, or every key in _packages is contained in existing packages, return
-            if (_packages.Count == 0 ||
-                _packages.All(p => existingPackages.Keys?.Contains(p.Key) ?? true))
-            {
-                return;
-            }
-
             _packages = _packages.Where(p => existingPackages.Keys?.Contains(p.Key) == false).ToDictionary(d => d.Key, d => d.Value);
 
+            //No packages to add
+            if (_packages.Count == 0) return;
+
             var packages = GetPackagesSection();
             if (existingPackages.Count == 0)
             {