Small fix to arithmetic_analysis/newton_method.py

When you raise inside an except block you will get two traceback.

>>> try:
...     a = 1/0
... except ZeroDivisionError:
...     raise ZeroDivisionError("Not possible")
...
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
ZeroDivisionError: division by zero

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 4, in <module>
ZeroDivisionError: Not possible

Why? the except block is used to handle the exceptions, if you want to raise an exception inside it you need to use the from clause like so:

>>> try:
...     a = 1/0
... except ZeroDivisionError:
...     raise ZeroDivisionError("Not possible") from None
...
Traceback (most recent call last):
  File "<stdin>", line 4, in <module>
ZeroDivisionError: Not possible

Describe your change:

• Fix a bug or typo in an existing algorithm?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.