Update dependency gulp-sass to v6

Author: renovate[bot]

package-lock.json

@@ -71,7 +71,7 @@
     "gulp-postcss": "9.0.1",
     "gulp-rename": "2.1.0",
     "gulp-run": "1.7.1",
-    "gulp-sass": "5.1.0",
+    "gulp-sass": "6.0.1",
     "gulp-svgmin": "3.0.0",
     "highlight.js": "11.11.1",
     "html-to-react": "1.4.8",