refactor: remove GOPROXY injection logic from deploy.sh, already in Dockerfile

Dockerfile

@@ -2,6 +2,7 @@
 FROM golang:1.25-alpine AS builder
 WORKDIR /app
 COPY go.mod go.sum ./
+ENV GOPROXY=https://goproxy.cn,direct
 RUN go mod download
 COPY . .
 RUN CGO_ENABLED=0 go build -o pr-helper .

deploy.sh

@@ -60,25 +60,7 @@ setup_docker_mirror() {
 }
 
 # ----------------------------------------------------------
-# 3. 注入 Go 模块代理到 Dockerfile
-# ----------------------------------------------------------
-setup_go_proxy() {
-    local dockerfile="Dockerfile"
-    local proxy_env="GOPROXY=https://goproxy.cn,direct"
-
-    if grep -q "GOPROXY" "$dockerfile"; then
-        warn "Dockerfile 已配置 GOPROXY，跳过"
-        return
-    fi
-
-    info "注入 Go 模块代理到 Dockerfile..."
-    # 在 builder 阶段的 RUN go mod download 之前注入 ENV
-    sed -i "/^RUN go mod download$/i ENV ${proxy_env}" "$dockerfile"
-    info "Go 模块代理配置完成"
-}
-
-# ----------------------------------------------------------
-# 4. 读取 .env 配置文件
+# 3. 读取 .env 配置文件
 # ----------------------------------------------------------
 load_env() {
     if [ ! -f ".env" ]; then
@@ -152,7 +134,6 @@ main() {
 
     check_docker
     setup_docker_mirror
-    setup_go_proxy
     load_env
     build_and_start
 }