fix: 修复构建错误，构建时安装 rsync

build/cross/Dockerfile.arm64

@@ -37,6 +37,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     wget \
     xz-utils \
     file \
+    rsync \
     gcc-aarch64-linux-gnu \
     g++-aarch64-linux-gnu \
     libc6-dev-arm64-cross \

build/cross/Dockerfile.armv7

@@ -37,6 +37,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     wget \
     xz-utils \
     file \
+    rsync \
     gcc-arm-linux-gnueabihf \
     g++-arm-linux-gnueabihf \
     libc6-dev-armhf-cross \

build/cross/Dockerfile.x86_64

@@ -34,6 +34,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     llvm \
     wget \
     xz-utils \
+    rsync \
     # Autotools for libopus (requires autoreconf)
     autoconf \
     automake \