Update Java version in Javadoc publish workflow

Author: BenCodez

.github/workflows/publish-javadoc.yml

@@ -16,7 +16,7 @@ jobs:
         with:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           javadoc-branch: gh-pages
-          java-version: 17
+          java-version: 21
           target-folder: ''
           project: maven # or gradle
           # subdirectories: moduleA moduleB #for subdirectories support, needs to be run with custom command