Bump alpine from 3.21 to 3.22

Bumps alpine from 3.21 to 3.22.

---
updated-dependencies:
- dependency-name: alpine
  dependency-version: '3.22'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.21 AS build
+FROM alpine:3.22 AS build
 
 WORKDIR /app
 
@@ -12,7 +12,7 @@ RUN go mod init github.com/itbm/postgresql-backup-s3 \
 	&& go get github.com/robfig/cron/v3 \
 	&& go build -o out/go-cron
 
-FROM alpine:3.21
+FROM alpine:3.22
 LABEL maintainer="ITBM"
 
 RUN apk update \