chore(npm): update dependency @antora/cli to v3.1.15 (#75)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/actions/build-antora-site/action.yml

@@ -11,7 +11,7 @@ inputs:
     description: "@antora/cli and @antora/site-generator version."
     required: false
     # renovate: datasource=npm depName=@antora/cli
-    default: "3.1.14"
+    default: "3.1.15"
   kroki-version:
     description: "asciidoctor-kroki version."
     required: false