refactor(rollup): use rollup loadConfigFile API
refactor(rollup): use rollup loadConfigFile API

alexeagle/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs,alexeagle/rules_nodejs,bazelbuild/rules_nodejs,alexeagle/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs,alexeagle/rules_nodejs