drop existing schema if tests create it explicitly

The former test implementation relied on the order in which tests are
executed assuming that tests explicitly creating the schema were executed
first. This assumption leads to test failures on PHPUnit 10+ were tests
defined in parent classes are run first where they were run later with
PHPUnit 9.6.

Author: xabbuh

src/Symfony/Component/Cache/Tests/Adapter/DoctrineDbalAdapterTest.php

@@ -48,6 +48,10 @@ public function createCachePool(int $defaultLifetime = 0): CacheItemPoolInterfac
 
     public function testConfigureSchemaDecoratedDbalDriver()
     {
+        if (file_exists(self::$dbFile)) {
+            @unlink(self::$dbFile);
+        }
+
         $connection = DriverManager::getConnection(['driver' => 'pdo_sqlite', 'path' => self::$dbFile], $this->getDbalConfig());
         if (!interface_exists(Middleware::class)) {
             $this->markTestSkipped('doctrine/dbal v2 does not support custom drivers using middleware');
@@ -73,6 +77,10 @@ public function testConfigureSchemaDecoratedDbalDriver()
 
     public function testConfigureSchema()
     {
+        if (file_exists(self::$dbFile)) {
+            @unlink(self::$dbFile);
+        }
+
         $connection = DriverManager::getConnection(['driver' => 'pdo_sqlite', 'path' => self::$dbFile], $this->getDbalConfig());
         $schema = new Schema();
 
@@ -83,6 +91,10 @@ public function testConfigureSchema()
 
     public function testConfigureSchemaDifferentDbalConnection()
     {
+        if (file_exists(self::$dbFile)) {
+            @unlink(self::$dbFile);
+        }
+
         $otherConnection = $this->createConnectionMock();
         $schema = new Schema();
 
@@ -93,6 +105,10 @@ public function testConfigureSchemaDifferentDbalConnection()
 
     public function testConfigureSchemaTableExists()
     {
+        if (file_exists(self::$dbFile)) {
+            @unlink(self::$dbFile);
+        }
+
         $connection = DriverManager::getConnection(['driver' => 'pdo_sqlite', 'path' => self::$dbFile], $this->getDbalConfig());
         $schema = new Schema();
         $schema->createTable('cache_items');