Update Dockerfile.redis-proxy

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: bootjp

Dockerfile.redis-proxy

@@ -1,6 +1,8 @@
 FROM golang:latest AS build
 
 WORKDIR $GOPATH/src/app
+COPY go.mod go.sum ./
+RUN go mod download
 COPY . .
 
 RUN CGO_ENABLED=0 go build -o /redis-proxy ./cmd/redis-proxy/