try pages deploy

.gitlab-ci.yml

+stages:
+  - build
+  - deploy
+
+eleventy:
+  stage: build
+  image: node:lts-buster
+  cache:
+    key: "$CI_JOB_NAME"
+    paths:
+      - node_modules/
+  script:
+    - yarn install
+    - yarn build
+  artifacts:
+    paths:
+      - public/
+  only:
+    - main
+
+pages:
+  stage: deploy
+  script:
+  - echo 'Nothing to do...'
+  artifacts:
+    paths:
+    - public
+    expire_in: 1 day
+  only:
+    - main

package.json

@@ -4,5 +4,9 @@
     "entities": "^2.2.0",
     "moment": "^2.29.1",
     "xml-reader": "^2.4.3"
+  },
+  "scripts": {
+    "build": "npx @11ty/eleventy",
+    "serve": "npx @11ty/eleventy --serve"
   }
 }