Bump alpine from 3.20 to 3.21 (#23)

Bumps alpine from 3.20 to 3.21.

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.20
+FROM alpine:3.21
 
 RUN apk --no-cache add git git-lfs \
   && rm -rf /var/lib/apt/lists/*