Unsupported SQLAlchemy-Continuum>=1.4.0

[jma]

Describe the bug

SQLAlchemy-Continuum has a new version since few days. Using the last version (1.4.0), executing the tests in our invenio instance we got the following error:

self = <sqlalchemy_continuum.manager.VersioningManager object at 0x1082c9460>, conn = <sqlalchemy.engine.base.Connection object at 0x10c522280>, clauseelement = 'BEGIN', multiparams = [], params = {}, execution_options = immutabledict({})

    def track_association_operations(
        self, conn, clauseelement, multiparams, params, execution_options,
    ):

        if (
            not self.options['versioning'] and
            not self.options['native_versioning']
        ):
            return

>       if clauseelement.is_insert:
E       AttributeError: 'str' object has no attribute 'is_insert'

Using SQLAlchemy-Continuum == 1.3.15, everything works nicely.