Set VERSIONSUFFIX to docker by default

.github/workflows/docker.yml

@@ -36,7 +36,7 @@ jobs:
           VERSIONSUFFIX=docker
           if [[ $GITHUB_REF == refs/tags/* ]]; then
             VERSION=${GITHUB_REF#refs/tags/}
-            VERSIONSUFFIX=
+            VERSIONSUFFIX=none
           elif [[ $GITHUB_REF == refs/heads/* ]]; then
             VERSION=nightly
             VERSIONSUFFIX=docker.${{ github.run_number }}