add: project branch_slice

app/services/gitea/repository/branches/list_slice_service.rb

@@ -0,0 +1,22 @@
+class Gitea::Repository::Branches::ListSliceService < Gitea::ClientService
+  attr_reader :user, :repo
+
+  def initialize(user, repo)
+    @user = user
+    @repo = repo
+  end
+
+  def call
+    response = get(url, params)
+    render_200_response(response)
+  end
+
+  private
+  def params
+    Hash.new.merge(token: user.gitea_token)
+  end
+
+  def url
+    "/repos/#{user.login}/#{repo}/branches/branches_slice".freeze
+  end
+end