webpack - ignore vim swapfiles when watching for changes
webpack - ignore vim swapfiles when watching for changes

otherwise, using vim with local swapfiles triggers recompilation even when opening a file, not only changing

same as https://github.com/ManageIQ/ui-components/pull/370,
and https://github.com/ManageIQ/manageiq-ui-classic/pull/5275

ManageIQ/manageiq-ui-self_service,ManageIQ/manageiq-ui-service,ManageIQ/manageiq-ui-self_service,ManageIQ/manageiq-ui-service,ManageIQ/manageiq-ui-self_service,ManageIQ/manageiq-ui-service