bpo-41626: port shebang of tools from python2 to python3

Lib/encodings/rot_13.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """ Python Character Mapping Codec for ROT13.
 
 This codec de/encodes from str to str.

Mac/BuildScript/build-installer.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 This script is used to build "official" universal installers on macOS.
 

Modules/_sha3/cleanup.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2012   Christian Heimes (christian@python.org)
 # Licensed to PSF under a Contributor Agreement.
 #

Objects/typeslots.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 # Usage: typeslots.py < Include/typeslots.h typeslots.inc
 
 import sys, re

Parser/asdl_c.py

@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 """Generate C code from an ASDL description."""
 
 import os

Python/makeopcodetargets.py

@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 """Generate C code for the jump table of the threaded code interpreter
 (for compilers supporting computed gotos or "labels-as-values", such as gcc).
 """

Tools/gdb/libpython.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 '''
 From gdb 7 onwards, gdb's build can be configured --with-python, allowing gdb
 to be extended with Python code e.g. for library-specific data visualizations,

Tools/pynche/pynche

@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 """Run this file under Unix, or when debugging under Windows.
 Run the file pynche.pyw under Windows to inhibit the console window.

Tools/scripts/smelly.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Script checking that all symbols exported by libpython start with Py or _Py
 
 import subprocess