Deprecate snapshot.bill_schedule and use snapshot.hearings

[jessiclassy]

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[jessiclassy]

Tested a DROP query in a local DB dump:

DETAIL:  view app.bills depends on table snapshot.bill_schedule
materialized view app.bills_mv depends on table snapshot.bill_schedule
materialized view app.calendar_mv depends on materialized view app.bills_mv
view app.hearing_bills depends on materialized view app.bills_mv
materialized view app.hearing_bills_mv depends on materialized view app.bills_mv
view app.org_bill_dashboard_custom depends on materialized view app.bills_mv
materialized view app.committees_mv depends on table snapshot.bill_schedule
view bills_2025_2026 depends on table snapshot.bill_schedule
...

Steps:

1. Update mat view definitions (bills_mv, calendar_mv, hearing_bills, org_bill_dashboard_custom, committees_mv) to reference hearings, NOT bill schedule
2. Migrate DB with a file to drop and recreate mat views with UPDATED definitions
3. Finally drop bill schedule