chore(deps): update alpine docker tag to v3.20

Dockerfile

@@ -1,9 +1,9 @@
 # CI system runs using amd64, so this allows us to not need QEMU, but
 # will break builds on non-amd64 Linux systems (sorry).
-FROM --platform=amd64 alpine:3.19 as cacerts
+FROM --platform=amd64 alpine:3.20 as cacerts
 RUN apk add --no-cache ca-certificates
 
-FROM alpine:3.19
+FROM alpine:3.20
 ENTRYPOINT ["/usr/local/bin/minecraft-preempt"]
 COPY --from=cacerts /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/