Revert "docs: fix bug in transaction example (#3414)"

This reverts commit dcb4257.

The change doesn’t fix the bug it claims to (`finally` always runs) and introduces a resource leak if the `ROLLBACK` query fails. The related bug that a broken client can be returned to the pool remains unaffected either way.

Author: charmander

docs/pages/features/transactions.mdx

@@ -31,10 +31,10 @@ try {
   const insertPhotoValues = [res.rows[0].id, 's3.bucket.foo']
   await client.query(insertPhotoText, insertPhotoValues)
   await client.query('COMMIT')
-  client.release()
 } catch (e) {
   await client.query('ROLLBACK')
-  client.release()
   throw e
+} finally {
+  client.release()
 }
 ```