fix: typo prebuilt version 2.6.9
fix: typo prebuilt version 2.6.9


dazuma/ruby-docker,GoogleCloudPlatform/ruby-docker,GoogleCloudPlatform/ruby-docker,dazuma/ruby-docker,dazuma/ruby-docker,GoogleCloudPlatform/ruby-docker,GoogleCloudPlatform/ruby-docker,dazuma/ruby-docker