Remove unused imports in Alembic migration script

Cleaned up unused imports from the migration file to improve code readability and reduce unnecessary dependencies. This change has no impact on functionality but simplifies the codebase.

Author: VladimirFilonov

keep/api/models/db/migrations/versions/2025-03-13-12-53_72611d1dadf2.py

@@ -6,11 +6,6 @@
 
 """
 
-import sqlalchemy as sa
-import sqlalchemy_utils
-import sqlmodel
-from alembic import op
-
 # revision identifiers, used by Alembic.
 revision = "72611d1dadf2"
 down_revision = ("9f11356d8ed9", "aaec81b991bd")