Bumps [gulp-sourcemaps](https://github.com/gulp-sourcemaps/gulp-sourcemaps) from 2.6.4 to 2.6.5.
- [Release notes](https://github.com/gulp-sourcemaps/gulp-sourcemaps/releases)
- [Commits](https://github.com/gulp-sourcemaps/gulp-sourcemaps/compare/v2.6.4...v2.6.5)
Signed-off-by: dependabot[bot] <support@dependabot.com>