Bump gulp-sass from 5.0.0 to 5.1.0

Bumps [gulp-sass](https://github.com/dlmanning/gulp-sass) from 5.0.0 to 5.1.0.
- [Release notes](https://github.com/dlmanning/gulp-sass/releases)
- [Changelog](https://github.com/dlmanning/gulp-sass/blob/master/CHANGELOG.md)
- [Commits](dlmanning/gulp-sass@v5.0.0...v5.1.0)

---
updated-dependencies:
- dependency-name: gulp-sass
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -41,7 +41,7 @@
     "gulp-autoprefixer": "^8.0.0",
     "gulp-concat": "^2.6.1",
     "gulp-cssnano": "^2.1.3",
-    "gulp-sass": "^5.0.0",
+    "gulp-sass": "^5.1.0",
     "gulp-strip-css-comments": "^2.0.0",
     "gulp-uglify": "^3.0.2",
     "lint-staged": "^12.1.4",