bpo-39674: Update collections ABC deprecation doc (GH-18748)

bpo-39674: Update collections ABC deprecation doc (GH-18748) · python/cpython@2aa694d

Original file line number	Diff line number	Diff line change
@@ -33,10 +33,10 @@ Python's general purpose built-in containers, :class:`dict`, :class:`list`,
`33`	`33`	:class:`UserString` wrapper around string objects for easier string subclassing
`34`	`34`	`===================== ====================================================================`
`35`	`35`
`36`		`-.. deprecated-removed:: 3.3 3.9`
	`36`	`+.. deprecated-removed:: 3.3 3.10`
`37`	`37`	Moved :ref:`collections-abstract-base-classes` to the :mod:`collections.abc` module.
`38`	`38`	`For backwards compatibility, they continue to be visible in this module through`
`39`		`- Python 3.8.`
	`39`	`+ Python 3.9.`
`40`	`40`
`41`	`41`
`42`	`42`	:class:`ChainMap` objects