Update dependency gulp to v5

Author: renovate[bot]

package.json

@@ -46,7 +46,7 @@
         "beeper": "2.1.0",
         "cssnano": "5.1.12",
         "gscan": "4.43.1",
-        "gulp": "4.0.2",
+        "gulp": "5.0.0",
         "gulp-concat": "2.6.1",
         "gulp-livereload": "4.0.2",
         "gulp-postcss": "9.0.1",