enh(Dockerfile): bump alpine repos used to install dependencies

Dockerfile

@@ -8,7 +8,7 @@ RUN apk add --no-cache curl && \
 
 FROM $FROM
 ARG GOARCH
-ARG ALPINE_VERSION=v3.12
+ARG ALPINE_VERSION=v3.20
 LABEL maintainer="squat <lserven@gmail.com>"
 RUN echo -e "https://alpine.global.ssl.fastly.net/alpine/$ALPINE_VERSION/main\nhttps://alpine.global.ssl.fastly.net/alpine/$ALPINE_VERSION/community" > /etc/apk/repositories && \
     apk add --no-cache ipset iptables ip6tables graphviz font-noto