fix: 升级Go到1.24解决依赖版本兼容问题

backend/Dockerfile

@@ -1,11 +1,11 @@
-FROM golang:1.22-alpine AS builder
+FROM golang:1.24-alpine AS builder
 
 WORKDIR /app
 
 RUN apk add --no-cache git nodejs npm
 
 ENV GOPROXY=https://goproxy.cn,direct
-ENV GOTOOLCHAIN=auto
+ENV GOFLAGS=-buildvcs=false
 
 COPY backend/go.mod backend/go.sum ./
 RUN go mod download