fix: stan errors

src/Connection.php

@@ -37,9 +37,9 @@
 use Google\Cloud\Spanner\SpannerClient;
 use Google\Cloud\Spanner\Timestamp;
 use Google\Cloud\Spanner\Transaction;
+use Illuminate\Contracts\Database\Query\Expression;
 use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Database\Connection as BaseConnection;
-use Illuminate\Database\Query\Expression;
 use Illuminate\Database\Query\Grammars\Grammar as BaseQueryGrammar;
 use Illuminate\Database\QueryException;
 use Illuminate\Support\Arr;

src/Schema/ColumnDefinition.php

@@ -20,7 +20,7 @@
 
 namespace Colopl\Spanner\Schema;
 
-use Illuminate\Database\Query\Expression;
+use Illuminate\Contracts\Database\Query\Expression;
 use Illuminate\Database\Schema\ColumnDefinition as BaseColumnDefinition;
 
 /**

src/Schema/Grammar.php

@@ -858,7 +858,7 @@ protected function modifyGeneratedAs(Blueprint $blueprint, Fluent $column): ?str
 
         $expression = match (true) {
             $as === true => 'bit_reversed_positive',
-            $as instanceof Expression => $this->getValue($as),
+            $as instanceof ExpressionContract => $this->getValue($as),
             default => $as,
         };