fix: upgrade @antora/site-generator-default from 3.0.1 to 3.1.9

Snyk has created this PR to upgrade @antora/site-generator-default from 3.0.1 to 3.1.9.

See this package in yarn:
@antora/site-generator-default

See this project in Snyk:
https://app.snyk.io/org/devfile/project/152e9a0c-6b48-4553-993d-c668fa8bd215?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

package.json

@@ -2,7 +2,7 @@
   "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": "^3.1.9",
     "bootprint": "^4.0.4",
     "bootprint-json-schema": "^4.0.4",
     "glob-fs": "^0.1.7",