Update alpine Docker tag to v3.20.2

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:3.20.2@sha256:0a4eaa0eecf5f8c050e5bba433f58c052be7587ee8af3e8b3910ef9ab5fbe9f5 AS prod
 RUN apk add --no-cache ca-certificates
 
 # tracing config