fix(db-postgres): start transaction in v2-v3 migration only after drizzle prompts to avoid timeout (#12302)

When running the v2-v3 migration you might receive prompts for renaming
columns. Since we start a transaction before, you might end up with a
fail if you don't answer within your transaction session period timeout.
This moves the `getTransaction` call after prompts were answered, since
we don't have a reason to start it earlier.

packages/drizzle/src/postgres/predefinedMigrations/v2-v3/index.ts

@@ -36,7 +36,6 @@ type Args = {
  */
 export const migratePostgresV2toV3 = async ({ debug, payload, req }: Args) => {
   const adapter = payload.db as unknown as BasePostgresAdapter
-  const db = await getTransaction(adapter, req)
   const dir = payload.db.migrationDir
 
   // get the drizzle migrateUpSQL from drizzle using the last schema
@@ -89,6 +88,8 @@ export const migratePostgresV2toV3 = async ({ debug, payload, req }: Args) => {
     payload.logger.info(addColumnsStatement)
   }
 
+  const db = await getTransaction(adapter, req)
+
   await db.execute(sql.raw(addColumnsStatement))
 
   for (const collection of payload.config.collections) {