fix docker latest tagging (#372)

Reviewed-on: https://codeberg.org/Codeberg/pages-server/pulls/372
Co-authored-by: crapStone <me@crapstone.dev>
Co-committed-by: crapStone <me@crapstone.dev>

.woodpecker/build.yml

@@ -109,7 +109,7 @@ steps:
       evaluate: 'CI_COMMIT_PULL_REQUEST_LABELS contains "build_pr_image"'
       event: pull_request
 
-  docker-tag:
+  docker-release:
     depends_on: vendor
     image: woodpeckerci/plugin-docker-buildx:4.2.0
     settings:
@@ -123,4 +123,4 @@ steps:
       password:
         from_secret: bot_token
     when:
-      - event: [push]
+      - event: [tag]