Make dropForeignIdFor method complementary to foreignIdFor (laravel#54102)

* Update tests to properly assert that only the column is dropped

* Drop the column instead of the foreign key

Author: willrowe

src/Illuminate/Database/Schema/Blueprint.php

@@ -531,7 +531,7 @@ public function dropForeignIdFor($model, $column = null)
             $model = new $model;
         }
 
-        return $this->dropForeign([$column ?: $model->getForeignKey()]);
+        return $this->dropColumn($column ?: $model->getForeignKey());
     }
 
     /**

tests/Database/DatabaseSchemaBlueprintTest.php

@@ -444,7 +444,7 @@ public function testDropRelationshipColumnWithIncrementalModel()
         };
 
         $this->assertEquals([
-            'alter table `posts` drop foreign key `posts_user_id_foreign`',
+            'alter table `posts` drop `user_id`',
         ], $getSql(new MySqlGrammar));
     }
 
@@ -457,7 +457,7 @@ public function testDropRelationshipColumnWithUuidModel()
         };
 
         $this->assertEquals([
-            'alter table `posts` drop foreign key `posts_model_using_uuid_id_foreign`',
+            'alter table `posts` drop `model_using_uuid_id`',
         ], $getSql(new MySqlGrammar));
     }