Update alpine Docker tag to v3.20.1

deployment/Dockerfile

@@ -27,7 +27,7 @@ COPY pkg ./pkg
 RUN go install .
 
 # production image ############################################
-FROM alpine:3.15.4@sha256:4edbd2beb5f78b1014028f4fbb99f3237d9561100b6881aabbf5acce2c4f9454 AS prod
+FROM alpine:3.20.1@sha256:cf3f1802132e21fa51a6edd5b0c41084de134959fddf9dc5d9faf2920a2985b2 AS prod
 RUN apk add --no-cache ca-certificates
 
 # tracing config