Remove shebangs from scripts

These are not really necessary—users can always pass the script name to
the Python interpreter explicitly; not really portable; and not useful
anyway unless the execute permission bit is set on the files in
question.

examples/exception_handling.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 """
 cyipopt: Python wrapper for the Ipopt optimization package, written in Cython.

examples/hs071.py

@@ -1,4 +1,3 @@
-#! /usr/bin/env python
 # -*- coding: utf-8 -*-
 """
 cyipopt: Python wrapper for the Ipopt optimization package, written in Cython.

examples/hs071_scipy_jax.py

@@ -1,5 +1,3 @@
-#! /usr/bin/env python3
-
 import jax.numpy as np
 import jax
 from jax import jit, grad, jacfwd, jacrev

examples/lasso.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 """
 cyipopt: Python wrapper for the Ipopt optimization package, written in Cython.

setup.py

@@ -1,4 +1,3 @@
-#! /usr/bin/env python
 # -*- coding: utf-8 -*-
 """
 cyipopt: Python wrapper for the Ipopt optimization package, written in Cython.