Upgrade rsync-antora-reference action version to 0.0.20

Author: fmbenhassine

.github/workflows/deploy-docs.yml

@@ -36,7 +36,7 @@ jobs:
     - name: Copy the cache to be included in the site
       run: cp -rf build/antora/inject-collector-cache-config-extension/.cache build/site/
     - name: Publish Docs
-      uses: spring-io/spring-doc-actions/[email protected].18
+      uses: spring-io/spring-doc-actions/[email protected].20
       with:
         docs-username: ${{ secrets.DOCS_USERNAME }}
         docs-host: ${{ secrets.DOCS_HOST }}