fix: update the workflow to Node 20 actions because Node 16 reached end of life

https://github.com/osscameroon/js-generator/actions/runs/8132746116?pr=264

https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

actions/setup-java#533

https://stackoverflow.com/questions/77897660/node-js-16-actions-are-deprecated-please-update-the-following-actions-to-use-no

Author: FanJups

.github/workflows/javadoc.yml

@@ -10,9 +10,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up JDK 17
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
           java-version: 17
@@ -27,4 +27,4 @@ jobs:
         run: |
           mvn clean site -B -e -X --projects 'jsgenerator-core'
         env:
-          MAVEN_SITE_GITHUB_OAUTH_TOKEN: ${{ secrets.MAVEN_SITE_GITHUB_OAUTH_TOKEN }}
+          MAVEN_SITE_GITHUB_OAUTH_TOKEN: ${{ secrets.MAVEN_SITE_GITHUB_OAUTH_TOKEN }}