bpo-39976: Add **other_popen_kwargs to subprocess docs (GH-20145)

(cherry picked from commit 4654500)

Co-authored-by: Zackery Spytz <[email protected]>

Author: miss-islington

Doc/library/subprocess.rst

@@ -40,7 +40,7 @@ compatibility with older versions, see the :ref:`call-function-trio` section.
 .. function:: run(args, *, stdin=None, input=None, stdout=None, stderr=None,\
                   capture_output=False, shell=False, cwd=None, timeout=None, \
                   check=False, encoding=None, errors=None, text=None, env=None, \
-                  universal_newlines=None)
+                  universal_newlines=None, **other_popen_kwargs)
 
    Run the command described by *args*.  Wait for command to complete, then
    return a :class:`CompletedProcess` instance.
@@ -1049,7 +1049,8 @@ Prior to Python 3.5, these three functions comprised the high level API to
 subprocess. You can now use :func:`run` in many cases, but lots of existing code
 calls these functions.
 
-.. function:: call(args, *, stdin=None, stdout=None, stderr=None, shell=False, cwd=None, timeout=None)
+.. function:: call(args, *, stdin=None, stdout=None, stderr=None, \
+                   shell=False, cwd=None, timeout=None, **other_popen_kwargs)
 
    Run the command described by *args*.  Wait for command to complete, then
    return the :attr:`~Popen.returncode` attribute.
@@ -1075,7 +1076,9 @@ calls these functions.
    .. versionchanged:: 3.3
       *timeout* was added.
 
-.. function:: check_call(args, *, stdin=None, stdout=None, stderr=None, shell=False, cwd=None, timeout=None)
+.. function:: check_call(args, *, stdin=None, stdout=None, stderr=None, \
+                         shell=False, cwd=None, timeout=None, \
+                         **other_popen_kwargs)
 
    Run command with arguments.  Wait for command to complete. If the return
    code was zero then return, otherwise raise :exc:`CalledProcessError`. The
@@ -1106,7 +1109,8 @@ calls these functions.
 
 .. function:: check_output(args, *, stdin=None, stderr=None, shell=False, \
                            cwd=None, encoding=None, errors=None, \
-                           universal_newlines=None, timeout=None, text=None)
+                           universal_newlines=None, timeout=None, text=None, \
+                           **other_popen_kwargs)
 
    Run command with arguments and return its output.