Remove the stale directory (pyarrow_files) (#11163)

.gitignore

@@ -1,7 +1,6 @@
 # The build output should clearly not be checked in
 /bazel-*
 /python/ray/core
-/python/ray/pyarrow_files/
 /python/ray/pickle5_files/
 /python/ray/thirdparty_files/
 /python/ray/jars/

ci/travis/format.sh

@@ -261,12 +261,12 @@ else
 fi
 
 # Ensure import ordering
-# Make sure that for every import psutil; import setpproctitle
+# Make sure that for every import psutil; import setproctitle
 # There's a import ray above it.
 
 PYTHON_EXECUTABLE=${PYTHON_EXECUTABLE:-python}
 
-$PYTHON_EXECUTABLE ci/travis/check_import_order.py . -s ci -s python/ray/pyarrow_files -s python/ray/thirdparty_files -s python/build -s lib
+$PYTHON_EXECUTABLE ci/travis/check_import_order.py . -s ci -s python/ray/thirdparty_files -s python/build -s lib
 
 if ! git diff --quiet &>/dev/null; then
     echo 'Reformatted changed files. Please review and stage the changes.'