ci: optimize leak sanitizer docker image for space

tools/ci/images/leak_sanitizer/Dockerfile

@@ -28,8 +28,8 @@ RUN clang --version  \
     && ninja --version \
     && mold --version
 
-RUN git clone --depth=1 https://github.com/llvm/llvm-project.git -b llvmorg-20.1.8
-RUN cd llvm-project/  \
+RUN git clone --depth=1 https://github.com/llvm/llvm-project.git -b llvmorg-20.1.8  \
+    && cd llvm-project/  \
     && rm -rf build/ \
     && mkdir build/ \
     && cd build/ \
@@ -45,7 +45,7 @@ RUN cd llvm-project/  \
     -DLIBCXX_INSTALL_MODULES=ON \
     -DLIBCXXABI_USE_LLVM_UNWINDER=OFF \
     -DLLVM_USE_SANITIZER=Leaks \
-    ../runtimes &&\
+    ../runtimes && \
     ninja cxx cxxabi && \
     && ninja -C build install-cxx install-cxxabi\
     && rm -rf /usr/src/llvm-project/