Issue #17047: removed doubled words in Doc/*, Mac/*, and Tool/*

found by Serhiy Storchaka and Matthew Barnett

Doc/c-api/intro.rst

@@ -433,7 +433,7 @@ and lose important information about the exact cause of the error.
 .. index:: single: sum_sequence()
 
 A simple example of detecting exceptions and passing them on is shown in the
-:c:func:`sum_sequence` example above.  It so happens that that example doesn't
+:c:func:`sum_sequence` example above.  It so happens that this example doesn't
 need to clean up any owned references when it detects an error.  The following
 example function shows some error cleanup.  First, to remind you why you like
 Python, we show the equivalent Python code::

Doc/c-api/long.rst

@@ -189,7 +189,7 @@ All integers are implemented as "long" integer objects of arbitrary size.
 
 .. c:function:: size_t PyLong_AsSize_t(PyObject *pylong)
 
-   Return a C :c:type:`size_t` representation of of *pylong*.  *pylong* must be
+   Return a C :c:type:`size_t` representation of *pylong*.  *pylong* must be
    an instance of :c:type:`PyLongObject`.
 
    Raise :exc:`OverflowError` if the value of *pylong* is out of range for a
@@ -201,7 +201,7 @@ All integers are implemented as "long" integer objects of arbitrary size.
    .. index::
       single: OverflowError (built-in exception)
 
-   Return a C :c:type:`unsigned PY_LONG_LONG` representation of of *pylong*.
+   Return a C :c:type:`unsigned PY_LONG_LONG` representation of *pylong*.
    *pylong* must be an instance of :c:type:`PyLongObject`.
 
    Raise :exc:`OverflowError` if the value of *pylong* is out of range for an

Doc/library/xml.dom.rst

@@ -357,7 +357,7 @@ All of the components of an XML document are subclasses of :class:`Node`.
 
    Add a new child node to this node at the end of the list of
    children, returning *newChild*. If the node was already in
-   in the tree, it is removed first.
+   the tree, it is removed first.
 
 
 .. method:: Node.insertBefore(newChild, refChild)