fix: use print() function in both Python 2 and Python 3 (#18395)

Legacy print statements are syntax errors in Python 3 but print() function works as expected in both Python 2 and Python 3.

Old style exceptions are syntax errors in Python 3 but new style exceptions work as expected in both Python 2 and Python 3.

build/npm-run.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+from __future__ import print_function
 import os
 import subprocess
 import sys
@@ -13,6 +14,6 @@ args = [cmd, "run",
     ] + sys.argv[1:]
 try:
     subprocess.check_output(args, stderr=subprocess.STDOUT)
-except subprocess.CalledProcessError, e:
+except subprocess.CalledProcessError as e:
     print("NPM script '" + sys.argv[2] + "' failed with code '" + str(e.returncode) + "':\n" + e.output)
     sys.exit(e.returncode)