Downgrade gh-pages from 6 to 5

v6 requires higher NodeJS version, but we need to upgrade the demo to use higher NodeJS first

Author: D-Pow

package-lock.json

@@ -54,7 +54,7 @@
     "core-js": "^3.21.1",
     "coveralls": "^3.1.1",
     "docdash": "^1.2.0",
-    "gh-pages": "^6.3.0",
+    "gh-pages": "^5.0.0",
     "jest": "^27.5.1",
     "jsdoc": "^3.6.10",
     "shelljs": "^0.8.5",