Script to migrate legacy customers to new pricing

[Betree]

Resolve opencollective/opencollective#8681

[sentry]

Bug: The database query at line 416 will fail if legacyHostToMigrate is empty, as the Kysely version used generates invalid SQL for empty IN clauses.
_{Severity: HIGH}

Suggested Fix

Wrap the .where('Collectives.id', 'in', legacyHostToMigrate) call in a conditional guard to ensure it only runs when the legacyHostToMigrate array is not empty, for example: .$if(legacyHostToMigrate.length > 0, qb => qb.where('Collectives.id', 'in', legacyHostToMigrate)).

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: scripts/billing/migrate-to-new-pricing.ts#L416

Potential issue: The database query on line 416 uses a `.where('Collectives.id', 'in',
legacyHostToMigrate)` clause. The version of Kysely in use (`0.28.14`) is known to
generate invalid SQL (`WHERE ... IN ()`) when the provided array is empty, which causes
a runtime database error and crashes the script. The `legacyHostToMigrate` array can
realistically be empty if, for example, the script is run after all migrations are
complete or if all candidate hosts are marked to be skipped. This will cause the
migration script to fail.

_{Did we get this right? 👍 / 👎 to inform future reviews.}