Remove usage of deprecated setuptools sandbox

The sandbox module has been deprecated for several Python versions and
is now removed.

Author: glubsy

build.py

@@ -10,14 +10,14 @@
 import shutil
 from multiprocessing import Pool
 
-from setuptools import sandbox
 from hscommon import sphinxgen
 from hscommon.build import (
     add_to_pythonpath,
     print_and_do,
     fix_qt_resource_file,
 )
 from hscommon import loc
+import subprocess
 
 
 def parse_args():
@@ -118,7 +118,7 @@ def build_normpo():
 def build_pe_modules():
     print("Building PE Modules")
     # Leverage setup.py to build modules
-    sandbox.run_setup("setup.py", ["build_ext", "--inplace"])
+    subprocess.check_call([sys.executable, "setup.py", "build_ext", "--inplace"])
 
 
 def build_normal():