CI/CircleCI: Show at the end of the build ccache stats of current build

(cherry picked from commit 0dee695f3b)

.circleci/config.yml

@@ -120,6 +120,7 @@ jobs:
             export CCACHE_CPP2=yes
             export USE_CCACHE=1
             export PATH=/usr/lib/ccache:$PATH
+            ccache -z
             ccache -s
             git config user.email "circleci@build.bot" && git config user.name "Circle CI"
             $CXX --version