chore(deps): pin dependency gh-pages to 6.0.0

[skip ci]

Author: renovate[bot]

package.json

@@ -91,7 +91,7 @@
     "eslint-plugin-react-hooks": "4.6.0",
     "eslint-plugin-simple-import-sort": "7.0.0",
     "eslint-plugin-testing-library": "5.11.1",
-    "gh-pages": "^6.0.0",
+    "gh-pages": "6.0.0",
     "graphql": "16.3.0",
     "husky": "7.0.4",
     "identity-obj-proxy": "3.0.0",