make vcpkg cache path

dev/vcpkg/docker/gha-centos-7.dockerfile

@@ -13,14 +13,16 @@ RUN sed -i \
 
 RUN yum install -y git patch wget sudo java-1.8.0-openjdk-devel
 
-# build
 RUN git clone --depth=1 https://github.com/apache/incubator-gluten /opt/gluten
 
 RUN echo "check_certificate = off" >> ~/.wgetrc
-# deps
+
 RUN cd /opt/gluten && bash ./dev/vcpkg/setup-build-depends.sh
 
-# vcpkg env
+# An actual path used for vcpkg cache.
+RUN mkdir -p /var/cache/vcpkg
+
+# Set vcpkg cache path.
 ENV VCPKG_BINARY_SOURCES=clear;files,/var/cache/vcpkg,readwrite
 
 # Build arrow, then install the native libs to system paths and jar package to .m2/ directory.