Remove SQLAlchemy < 1.4 imports and comments

flask_admin/contrib/sqla/filters.py

@@ -207,7 +207,6 @@ def apply(self, query, value, alias=None):
 class DateNotBetweenFilter(DateBetweenFilter):
     def apply(self, query, value, alias=None):
         start, end = value
-        # ~between() isn't possible until sqlalchemy 1.0.0
         return query.filter(not_(self.get_column(alias).between(start, end)))
 
     def operation(self):

flask_admin/contrib/sqla/tools.py

@@ -1,17 +1,12 @@
 import types
 
 from sqlalchemy import tuple_, or_, and_, inspect
-try:
-    # Attempt _class_resolver import from SQLALchemy 1.4/2.0 module architecture.
-    from sqlalchemy.orm.clsregistry import _class_resolver
-except ImportError:
-    # If 1.4/2.0 module import fails, fall back to <1.3.x architecture.
-    from sqlalchemy.ext.declarative.clsregistry import _class_resolver
+from sqlalchemy.orm.clsregistry import _class_resolver
 from sqlalchemy.ext.hybrid import hybrid_property
 try:
-    # Attempt ASSOCATION_PROXY import from pre-2.0 release
     from sqlalchemy.ext.associationproxy import ASSOCIATION_PROXY
 except ImportError:
+    # SQLAlchemy 2.0
     from sqlalchemy.ext.associationproxy import AssociationProxyExtensionType
     ASSOCIATION_PROXY = AssociationProxyExtensionType.ASSOCIATION_PROXY
 from sqlalchemy.sql.operators import eq