Update dependency gulp-sass to v6

Author: renovate[bot]

package.json

@@ -16,7 +16,7 @@
   "devDependencies": {
     "gulp": "4.0.2",
     "gulp-cli": "2.3.0",
-    "gulp-sass": "5.1.0",
+    "gulp-sass": "6.0.0",
     "sass": "1.60.0",
     "ts-node": "10.9.1",
     "typescript": "5.0.3"