fix(terser): terser_minified should support .mjs files when running on directory (#1264)
fix(terser): terser_minified should support .mjs files when running on directory (#1264)

Directory mode should match file mode which already allows .mjs files

```
def _filter_js(files):
    return [f for f in files if f.is_directory or f.extension == "js" or f.extension == "mjs"]
```
alexeagle/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs,alexeagle/rules_nodejs,alexeagle/rules_nodejs,alexeagle/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs