py-astroid: updated to 2.6.1

What's New in astroid 2.6.1?
============================
Release date: 2021-06-29

* Fix issue with ``TypedDict`` for Python 3.9+

What's New in astroid 2.6.0?
============================
Release date: 2021-06-22

* Appveyor and travis are no longer used in the continuous integration

* ``setuptools_scm`` has been removed and replaced by ``tbump`` in order to not
  have hidden runtime dependencies to setuptools

* ``NodeNg``, the base node class, is now accessible from ``astroid`` or
  ``astroid.nodes`` as it can be used for typing.

* Update enum brain to improve inference of .name and .value dynamic class
  attributes

* Removed ``Repr``, ``Exec``, and ``Print`` nodes as the ``ast`` nodes
  they represented have been removed with the change to Python 3

* Deprecate ``Ellipsis`` node. It will be removed with the next minor release.
  Checkers that already support Python 3.8+ work without issues. It's only
  necessary to remove all references to the ``astroid.Ellipsis`` node.
  This changes will make development of checkers easier as the resulting tree for Ellipsis
  will no longer depend on the python version. **Background**: With Python 3.8 the
  ``ast.Ellipsis`` node, along with ``ast.Str``, ``ast.Bytes``, ``ast.Num``,
  and ``ast.NamedConstant`` were merged into ``ast.Constant``.

* Deprecated ``Index`` and ``ExtSlice`` nodes. They will be removed with the
  next minor release. Both are now part of the ``Subscript`` node.
  Checkers that already support Python 3.9+ work without issues.
  It's only necessary to remove all references to the ``astroid.Index`` and
  ``astroid.ExtSlice`` nodes. This change will make development of checkers
  easier as the resulting tree for ``ast.Subscript`` nodes will no longer
  depend on the python version. **Background**: With Python 3.9 ``ast.Index``
  and ``ast.ExtSlice`` were merged into the ``ast.Subscript`` node.

* Updated all Match nodes to be internally consistent.

* Add ``Pattern`` base class.

What's New in astroid 2.5.8?
============================
Release date: 2021-06-07

* Improve support for Pattern Matching

* Add lineno and col_offset for ``Keyword`` nodes and Python 3.9+

* Add global inference cache to speed up inference of long statement blocks

* Add a limit to the total number of nodes inferred indirectly as a result
  of inferring some node

(adam)