docker: use alpine packages for Rust builder to fix linux/386 builds (#8837)

The upstream rust:alpine manifest list no longer includes linux/386,
breaking multi-platform builds. Switch the Rust volume server builder
stage to alpine:3.23 and install Rust toolchain via apk instead.
Also adds openssl-dev which is needed for the build.

docker/Dockerfile.go_build

@@ -16,15 +16,16 @@ RUN cd /go/src/github.com/seaweedfs/seaweedfs/weed \
   && export LDFLAGS="-X github.com/seaweedfs/seaweedfs/weed/util/version.COMMIT=$(git rev-parse --short HEAD)" \
   && CGO_ENABLED=0 go install -tags "$TAGS" -ldflags "-extldflags -static ${LDFLAGS}"
 
-# Rust volume server builder (amd64/arm64 only)
-FROM rust:1-alpine as rust_builder
+# Rust volume server builder. Alpine packages avoid depending on the
+# upstream rust:alpine manifest list, which no longer includes linux/386.
+FROM alpine:3.23 as rust_builder
 ARG TARGETARCH
-RUN apk add musl-dev protobuf-dev git
 COPY --from=builder /go/src/github.com/seaweedfs/seaweedfs/seaweed-volume /build/seaweed-volume
 COPY --from=builder /go/src/github.com/seaweedfs/seaweedfs/proto /build/proto
 WORKDIR /build/seaweed-volume
 ARG TAGS
 RUN if [ "$TARGETARCH" = "amd64" ] || [ "$TARGETARCH" = "arm64" ]; then \
+      apk add --no-cache musl-dev openssl-dev protobuf-dev git rust cargo; \
       if [ "$TAGS" = "5BytesOffset" ]; then \
         cargo build --release; \
       else \