Repairs one in-library deprecation warning regarding
mapper propagation of options

raises maxfail to 250, as 25 is too low when we are trying
to address many errors at once.   the 25 was originally
due to the fact that our fixtures would be broken after
that many failures in most cases, which today should not
be the case nearly as often.

Change-Id: I26affddf42e2cae2aaf9561633e9b8cd431eb189

Fixed regression where the use of a :class:`_orm.hybrid_property` attribute
or a mapped :func:`_orm.composite` attribute as a key passed to the
:meth:`_dml.Update.values` method for an ORM-enabled :class:`_dml.Update`
statement, as well as when using it via the legacy
:meth:`_orm.Query.update` method, would be processed for incoming
ORM/hybrid/composite values within the compilation stage of the UPDATE
statement, which meant that in those cases where caching occurred,
subsequent invocations of the same statement would no longer receive the
correct values. This would include not only hybrids that use the
:meth:`_orm.hybrid_property.update_expression` method, but any use of a
plain hybrid attribute as well. For composites, the issue instead caused a
non-repeatable cache key to be generated, which would break caching and
could fill up the statement cache with repeated statements.

The :class:`_dml.Update` construct now handles the processing of key/value
pairs passed to :meth:`_dml.Update.values` and
:meth:`_dml.Update.ordered_values` up front when the construct is first
generated, before the cache key has been generated so that the key/value
pairs are processed each time, and so that the cache key is generated
against the individual column/value pairs that will ultimately be
used in the statement.

Fixes: #7209
Change-Id: I08f248d1d60ea9690b014c21439b775d951fb9e5

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #6899
Change-Id: I965af321fb36d9645fe3fc2675ad9943f24e32f2

Fixed issue in mypy plugin to improve upon some issues detecting ``Enum()``
SQL types containing custom Python enumeration classes. Pull request
courtesy Hiroshi Ogawa.

Fixes: #6435
Closes: #7048
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7048
Pull-request-sha: 59f5c89688792f6af3b07488d5cf97f8f2e964dc

Change-Id: I05adbec74ceac1ecfdc5a242bfe7aa4b2eb805e4

to ``scoped_session`` and ``async_scoped_session``.

Fixes: #7103
Change-Id: If80481771d9b428f2403af3862e0479bd069257e

Improve the interface used by adapted drivers, like the asyncio ones,
to access the actual connection object returned by the driver.

The :class:`_engine._ConnectionRecord` and
:class:`_engine._ConnectionFairy` now have two new attributes:

* ``dbapi_connection`` always represents a DBAPI compatible
object.  For pep-249 drivers, this is the DBAPI connection as it always
has been, previously accessed under the ``.connection`` attribute.
For asyncio drivers that SQLAlchemy adapts into a pep-249 interface,
the returned object will normally be a SQLAlchemy adaption object
called :class:`_engine.AdaptedConnection`.
* ``driver_connection`` always represents the actual connection object
maintained by the third party pep-249 DBAPI or async driver in use.
For standard pep-249 DBAPIs, this will always be the same object
as that of the ``dbapi_connection``.  For an asyncio driver, it will be
the underlying asyncio-only connection object.

The ``.connection`` attribute remains available and is now a legacy alias
of ``.dbapi_connection``.

Fixes: #6832
Change-Id: Ib72f97deefca96dce4e61e7c38ba430068d6a82e

Added new methods :meth:`_orm.Session.scalars`,
:meth:`_engine.Connection.scalars`, :meth:`_asyncio.AsyncSession.scalars`
and :meth:`_asyncio.AsyncSession.stream_scalars`, which provide a short cut
to the use case of receiving a row-oriented :class:`_result.Result` object
and converting it to a :class:`_result.ScalarResult` object via the
:meth:`_engine.Result.scalars` method, to return a list of values rather
than a list of rows. The new methods are analogous to the long existing
:meth:`_orm.Session.scalar` and :meth:`_engine.Connection.scalar` methods
used to return a single value from the first row only. Pull request
courtesy Miguel Grinberg.

Fixes: #6990
Closes: #6991
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/6991
Pull-request-sha: b3e0bb3042c55b0cc5af6a25cb3f31b929f88a47

Change-Id: Ia445775e24ca964b0162c2c8e5ca67dd1e39199f

Added loader options to :meth:`_orm.Session.merge` and
:meth:`_asyncio.AsyncSession.merge`, which will apply the given loader
options to the ``get()`` used internally by merge, allowing eager loading
of relationships etc. to be applied when the merge process loads a new
object. Pull request courtesy Daniel Stone.

Fixes: #6955
Closes: #6957
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/6957
Pull-request-sha: ab4d96cd5da9a5dd01112b8dcd6514db64aa8d9f

Change-Id: I5b94dfda1088a8bc6396e9fd9a072827df1f8680

while I dont like this approach very much, people will likely
be asking for it a lot, so represent the most correct and
efficient form we can handle right now.

Added missing ``**kw`` arguments to the
:meth:`_asyncio.AsyncSession.connection` method.

Change-Id: Idadae2a02a4d96ecb96a5723ce64d017ab4c6217
References: https://github.com/sqlalchemy/sqlalchemy/discussions/6965

1798c3cf1c added __slots__ to the base which then
caused af0824fd79 to fail.  as we can't use an assignable
class variable with slots, remove slots from AsyncSession
which is how this class was working anyway.

Fixes: #6967
Change-Id: I4e0adab923db8e77cf748a8728e253258838e8f1