Revert "[verified] feat: add external calendar subscriptions"

This reverts commit 583b6a8a9d.

migrations/versions/0020_calendar_subscriptions.py

@@ -1,42 +0,0 @@
-"""restore persistent external calendar subscriptions
-
-Revision ID: 0020_calendar_subscriptions
-Revises: 0019_backup_imports
-"""
-
-import sqlalchemy as sa
-from alembic import op
-
-revision = "0020_calendar_subscriptions"
-down_revision = "0019_backup_imports"
-branch_labels = None
-depends_on = None
-
-
-def upgrade() -> None:
-    op.create_table(
-        "calendar_subscriptions",
-        sa.Column("id", sa.Uuid(), nullable=False),
-        sa.Column("user_id", sa.Uuid(), nullable=False),
-        sa.Column("name", sa.String(length=120), nullable=False),
-        sa.Column("url", sa.Text(), nullable=False),
-        sa.Column("color", sa.String(length=32), nullable=False),
-        sa.Column("enabled", sa.Boolean(), nullable=False),
-        sa.Column("ics_cache", sa.Text(), nullable=True),
-        sa.Column("etag", sa.String(length=512), nullable=True),
-        sa.Column("last_modified", sa.String(length=512), nullable=True),
-        sa.Column("refreshed_at", sa.DateTime(timezone=True), nullable=True),
-        sa.Column("last_error", sa.Text(), nullable=True),
-        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
-        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
-        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
-        sa.PrimaryKeyConstraint("id"),
-    )
-    op.create_index(
-        "ix_calendar_subscriptions_user_id", "calendar_subscriptions", ["user_id"]
-    )
-
-
-def downgrade() -> None:
-    op.drop_index("ix_calendar_subscriptions_user_id", table_name="calendar_subscriptions")
-    op.drop_table("calendar_subscriptions")