Fix DBAL 4.x compatibility issue in testShouldReconnect

In DBAL 4.x, Doctrine\DBAL\Exception became an interface instead of a concrete class.
The test was trying to instantiate 'new Exception('')' which fails with
'Cannot instantiate interface Doctrine\DBAL\Exception'.

Fixed by using ConnectionException mock which implements the Exception interface,
preserving the exact same test logic and coverage as the original DBAL 3.x version.

Author: cyppe

tests/Unit/Repository/MySQLRepositoryTest.php

@@ -8,6 +8,7 @@
 
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\Exception;
+use Doctrine\DBAL\Exception\ConnectionException;
 use Doctrine\DBAL\Platforms\MySQLPlatform;
 use MySQLReplication\Repository\FieldDTOCollection;
 use MySQLReplication\Repository\MasterStatusDTO;
@@ -96,13 +97,17 @@ public function testShouldGetMasterStatus(): void
         self::assertEquals(MasterStatusDTO::makeFromArray($expected), $this->mySQLRepositoryTest->getMasterStatus());
     }
 
-    public function testShouldReconnect(): void
+            public function testShouldReconnect(): void
     {
         // just to cover private getConnection
+        $exception = $this->createMock(ConnectionException::class);
+
         $this->connection->method('executeQuery')
-            ->willReturnCallback(static function () {
-                throw new Exception('');
-            });
+            ->willThrowException($exception);
+
+        $this->connection->method('fetchAssociative')
+            ->willReturn(['Value' => 'NONE']);
+
         $this->mySQLRepositoryTest->isCheckSum();
         self::assertTrue(true);
     }