Merge pull request #1 from locohamster/update-to-alpine3.21

Update Dockerfile base image alpine3.20->alpine3.21

Author: locohamster

5/alpine/Dockerfile

@@ -1,6 +1,6 @@
 # https://docs.ghost.org/faq/node-versions/
 # https://github.com/nodejs/Release (looking for "LTS")
-FROM node:18-alpine3.20
+FROM node:18-alpine3.21
 
 RUN apk add --no-cache \
 # add "bash" for "[["