Bump spring-io/spring-doc-actions from 0.0.20 to 0.0.21

Updates the spring-doc-actions reference in the documentation workflow
to use the latest version (v0.0.21) for both the rsync-antora-reference
and bust-cloudflare-antora-cache actions.

Author: cppwfs

.github/workflows/spring-build-and-deploy-docs.yml

@@ -51,15 +51,15 @@ jobs:
         run: cp -rf build/antora/inject-collector-cache-config-extension/.cache build/site/
 
       - name: Publish Docs
-        uses: spring-io/spring-doc-actions/rsync-antora-reference@v0.0.20
+        uses: spring-io/spring-doc-actions/rsync-antora-reference@v0.0.21
         with:
           docs-username: ${{ secrets.DOCS_USERNAME }}
           docs-host: ${{ secrets.DOCS_HOST }}
           docs-ssh-key: ${{ secrets.DOCS_SSH_KEY }}
           docs-ssh-host-key: ${{ secrets.DOCS_SSH_HOST_KEY }}
 
       - name: Bust Cloudflare Cache
-        uses: spring-io/spring-doc-actions/bust-cloudflare-antora-cache@v0.0.20
+        uses: spring-io/spring-doc-actions/bust-cloudflare-antora-cache@v0.0.21
         with:
           context-root: ${{ github.event.repository.name }}
           cloudflare-zone-id: ${{ secrets.CLOUDFLARE_ZONE_ID }}