Upgrade bust-cloudflare-antora-cache action version to 0.0.20

Author: fmbenhassine

.github/workflows/deploy-docs.yml

@@ -43,7 +43,7 @@ jobs:
         docs-ssh-key: ${{ secrets.DOCS_SSH_KEY }}
         docs-ssh-host-key: ${{ secrets.DOCS_SSH_HOST_KEY }}
     - name: Bust Clouflare Cache
-      uses: spring-io/spring-doc-actions/[email protected].18
+      uses: spring-io/spring-doc-actions/[email protected].20
       with:
         context-root: spring-shell
         cloudflare-zone-id: ${{ secrets.CLOUDFLARE_ZONE_ID }}