Support SQLAlchemy 1.4

[Nothing4You]

Collecting what's needed for SQLAlchemy 1.4 here.

https://www.sqlalchemy.org/download.html
Version 1.3 is currently in maintenance state and will only receive critical bug fixes.
1.4 is currently stable, with 2.0 currently being in development.
Once 2.0 ships, 1.3 will be EOL.

https://docs.sqlalchemy.org/en/14/changelog/migration_14.html

• FromClause.count() has been removed, was already deprecated in 1.3
  Fix use of deprecated SQLAlchemy functionality in tests #814
• https://docs.sqlalchemy.org/en/14/changelog/migration_14.html#change-4645
  SQLAlchemy 1.4 statements with .in_ operator not compiled correctly #577

Additional topics

• SQLAlchemy 1.4 introduces greenlet as dependency
  • greenlet does not yet build on Python 3.11, so our 3.11-dev tests will fail once we update SQLAlchemy and include greenlet
  • greenlet does not currently have a 1.x branch, dev is for 2.0. backport is requested in Consider releasing a new greenlet 1.1.3 version compatible with Python 3.11 python-greenlet/greenlet#305