run apk upgrade during build

Dockerfile

 FROM alpine:3.21
-RUN apk add --no-cache bash perl rsync wget xz && \
+RUN apk upgrade --no-cache && \
+    apk add --no-cache bash perl rsync wget xz && \
     adduser -u 1000 -D -H user
 USER user
 COPY files/ /
\ No newline at end of file