Dry up identical stubs

By removing the one that has fewer usages.

spec/support/helpers/stub_object_storage.rb

 # frozen_string_literal: true
 
 module StubObjectStorage
-  def stub_packages_object_storage(**params)
-    stub_object_storage_uploader(config: ::Gitlab.config.packages.object_store,
-                                  uploader: ::Packages::PackageFileUploader,
-                                  remote_directory: 'packages',
-                                  **params)
-  end
-
   def stub_dependency_proxy_object_storage(**params)
     stub_object_storage_uploader(config: ::Gitlab.config.dependency_proxy.object_store,
                                   uploader: ::DependencyProxy::FileUploader,

spec/tasks/gitlab/packages/migrate_rake_spec.rb

@@ -18,7 +18,7 @@ RSpec.describe 'gitlab:packages namespace rake task' do
 
     context 'object storage disabled' do
       before do
-        stub_packages_object_storage(enabled: false)
+        stub_package_file_object_storage(enabled: false)
       end
 
       it "doesn't migrate files" do
@@ -28,7 +28,7 @@ RSpec.describe 'gitlab:packages namespace rake task' do
 
     context 'object storage enabled' do
       before do
-        stub_packages_object_storage
+        stub_package_file_object_storage
       end
 
       it 'migrates local file to object storage' do

spec/uploaders/packages/package_file_uploader_spec.rb

@@ -15,7 +15,7 @@ RSpec.describe Packages::PackageFileUploader do
 
   context 'object store is remote' do
     before do
-      stub_packages_object_storage
+      stub_package_file_object_storage
     end
 
     include_context 'with storage', described_class::Store::REMOTE
@@ -29,7 +29,7 @@ RSpec.describe Packages::PackageFileUploader do
 
     context 'with object storage enabled' do
       before do
-        stub_packages_object_storage
+        stub_package_file_object_storage
       end
 
       it 'can store file remotely' do