fix: package.json & yarn.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-BRACEEXPANSION-9789073

Author: snyk-bot

package.json

@@ -2,11 +2,11 @@
   "dependencies": {
     "@antora/cli": "^3.0.0",
     "@antora/lunr-extension": "^1.0.0-alpha.3",
-    "@antora/site-generator-default": "^3.0.0",
+    "@antora/site-generator-default": "^3.1.8",
     "bootprint": "^4.0.4",
     "bootprint-json-schema": "^4.0.4",
     "glob-fs": "^0.1.7",
-    "gulp": "^4.0.2",
+    "gulp": "^5.0.0",
     "gulp-cli": "^2.3.0",
     "gulp-connect": "^5.7.0",
     "http-server": "^0.12.3"