chore(deps): update alpine:3.21 docker digest to a8560b3

Author: renovate[bot]

cmd/ssl-team-client/Dockerfile

@@ -8,7 +8,7 @@ COPY go.sum .
 RUN go install -v ./cmd/ssl-team-client
 
 # Start fresh from a smaller image
-FROM alpine:3.21@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099
+FROM alpine:3.21@sha256:a8560b36e8b8210634f77d9f7f9efd7ffa463e380b75e2e74aff4511df3ef88c
 COPY --from=build_go /go/bin/ssl-team-client /app/ssl-team-client
 USER 1000
 ENTRYPOINT ["/app/ssl-team-client"]