Cast to bigint on PostgreSQL to avoid issues with big integer IDs (#40)

* Cast to bigint on postgresql to avoid issues with big integer IDs

* Fix tests for sqlsrv

* Reversed it by mistake

* Remove leftover

* Revert changes to tests

(cherry picked from commit 3bb8083)

src/Relations/Postgres/IsPostgresRelation.php

@@ -22,7 +22,7 @@ protected function jsonColumn(Builder $query, Model $model, $column, $key)
         $sql = $query->getQuery()->getGrammar()->wrap($column);
 
         if ($model->getKeyName() === $key && in_array($model->getKeyType(), ['int', 'integer'])) {
-            $sql = '('.$sql.')::int';
+            $sql = '('.$sql.')::bigint';
         }
 
         if ($model->hasCast($key) && $model->getCasts()[$key] === 'uuid') {