musa: update ci doc (install ccache)

Signed-off-by: Xiaodong Ye <[email protected]>

Author: yeahdongcn

ci/README.md

@@ -60,7 +60,7 @@ docker run --privileged -it \
 Inside the container, execute the following commands:
 
 ```bash
-apt update -y && apt install -y bc cmake git python3.10-venv time unzip wget
+apt update -y && apt install -y bc cmake ccache git python3.10-venv time unzip wget
 git config --global --add safe.directory /ws
 GG_BUILD_MUSA=1 bash ./ci/run.sh /ci-results /ci-cache
 ```