Fix typos in the Lib directory as identified by codespell.

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>.
(cherry picked from commit 745c9d9dfc1ad6fdfdf1d07420c6273ff67fa5be)

Co-authored-by: Christian Clauss <cclauss@me.com>

A previous commit broke a check in sysconfig when building cpython itself.
This caused builds of the standard library modules to search a wrong
location (the installed location rather than the source directory) for
header files with the net effect that a ``make install``
incorrectly caused all extension modules to be rebuilt again and
with incorrect include file paths.

When building Python, we need two distinct "include" directories:
- source .h files
- install target for .h files

Note that this doesn't matter except when building Python from source.

Historically:
- source .h files were in the distutils scheme under 'include'
- the install directory was in the distutils.command.install scheme
    under 'headers'

GH-24549 merged these; sysconfig is now the single source of truth and
distutils is derived from it.

This commit introduces a "secret" scheme path, 'headers', which contains
the install target. It is only present when building Python.
The distutils code uses it if present, and falls back to 'include'.

Co-authored-by: Ned Deily <nad@python.org>
(cherry picked from commit 563bd5a4dcc6a26e47966cb66db64859902bce76)

Co-authored-by: Petr Viktorin <encukou@gmail.com>

With this patch, `distutils.command.install.INSTALL_SCHEMES` are loaded from
`sysconfig._INSTALL_SCHEMES`.

The distutils module is deprecated and will be removed in 3.12 (PEP 632).
This change makes the `sysconfig._INSTALL_SCHEMES` the single point of truth
for install schemes while keeping `distutils.command.install.INSTALL_SCHEMES`
exactly the same. If we, during the transition to the sysconfig, change
something, this makes sure that it also propagates to distutils until the
module gets removed.

Moreover, as discussed [on Discourse], Linux distros need to patch
distutils/sysconfig to make sure the packages will land in proper locations.
This patch makes it easier because it leaves only one location where install
schemes are defined which is much easier to patch/adjust.

[on Discourse]: https://discuss.python.org/t/pep-632-deprecate-distutils-module/5134

The implementation is slightly different than the plan but I think it's the
easiest way how to do it and it also makes the downstream patch simple,
flexible and easy to maintain.

It's also necessary to implement this before setuptools starts bundling
the distutils module so the default install schemes stay in the standard library.

The removed code from sysconfig does not seem to have any negative effect
because, honestly, it seems that nothing actually uses the install schemes
from sysconfig at all. There were many big changes in these modules where
they were trying to include packaging in stdlib and then reverted that.
Also, the test of distutils install command does not count with the different
locations which is good evidence that the reason to have this piece of code
is no longer valid.


https://bugs.python.org/issue41282

Add --with-platlibdir option to the configure script: name of the
platform-specific library directory, stored in the new sys.platlitdir
attribute. It is used to build the path of platform-specific dynamic
libraries and the path of the standard library.

It is equal to "lib" on most platforms. On Fedora and SuSE, it is
equal to "lib64" on 64-bit systems.

Co-Authored-By: Jan Matějek <jmatejek@suse.com>
Co-Authored-By: Matěj Cepl <mcepl@cepl.eu>
Co-Authored-By: Charalampos Stratakis <cstratak@redhat.com>

In distutils.command.install, replace "pliant children" (previously,
it was "pliant slaves") with "helpers".

<!-- issue-number: [bpo-34605](https://www.bugs.python.org/issue34605) -->
https://bugs.python.org/issue34605
<!-- /issue-number -->

* Replace "master process" with "parent process"
* Replace "master option mappings" with "main option mappings"
* Replace "master pattern object" with "main pattern object"
* ssl: replace "master" with "server"
* And some other similar changes