1.4 deprecated operators are not supported correctly

[rogalski]

SQLAlchemy 1.4 release notes: https://docs.sqlalchemy.org/en/14/changelog/changelog_14.html#change-8dd50c1cc4d512bf97b23fb0243619af

Several operators are renamed to achieve more consistent naming across SQLAlchemy.

The operator changes are:
    isfalse is now is_false
    isnot_distinct_from is now is_not_distinct_from
    istrue is now is_true
    notbetween is now not_between
    notcontains is now not_contains
    notendswith is now not_endswith
    notilike is now not_ilike
    notlike is now not_like
    notmatch is now not_match
    notstartswith is now not_startswith
    nullsfirst is now nulls_first
    nullslast is now nulls_last
    isnot is now is_not
    not_in_ is now not_in

Stubs needs to be updated:

Module "sqlalchemy.sql.expression" has no attribute "nulls_last"; maybe "nullslast"?

Version:

Successfully installed sqlalchemy-stubs-0.4