SchemaMigrationService and the schema_migrations table are dead code

[RUKAYAT-CODER]

src/migrations/schema-migration.service.ts defines SchemaMigrationService which queries/inserts/deletes from a schema_migrations table:

• The service is never injected or used anywhere in src/
• No migration creates a schema_migrations table (migrations use TypeORM's migrations table)

It's misleading dead code that also sits in the migrations directory (it had to be excluded from the migration glob in #1192).

Fix: remove the file (and src/migrations/entities/ if also unused), or wire it up and add the table if it's actually needed.

[sublime247]

I would love to resolve this issues