Bump library/alpine

Bumps the docker-dependencies group with 1 update in the /services/manager directory: library/alpine.


Updates `library/alpine` from 3.20 to 3.21

---
updated-dependencies:
- dependency-name: library/alpine
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: docker-dependencies
...

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Author: dependabot[bot]

services/manager/Dockerfile

@@ -29,7 +29,7 @@ RUN CGO_ENABLED=0 go build
 FROM alpine:latest as certs
 RUN apk --update add ca-certificates
 
-FROM docker.io/library/alpine:3.20
+FROM docker.io/library/alpine:3.21
 #Add repository label
 LABEL org.opencontainers.image.source "https://github.com/berops/claudie"
 #Add base image name as a label