code: private function addDefaultServerVersion(array $extensionConfigs, ContainerBuilder $container): array
      {
          $params = [];
  
          foreach ($extensionConfigs as $extensionConfig) {
              if (isset($extensionConfig['dbal']['connections']['default'])) {
                  $params[] = $extensionConfig['dbal']['connections']['default'];
              }
          }
  
          if (!empty($params)) {
              $params = array_merge(...$params);
          }
  
          $parameterBag = $container->getParameterBag();
  
          foreach ($params as $key => $value) {
              $params[$key] = $parameterBag->resolveValue($value);
          }
  
          // If there are no DB credentials yet (install tool), we have to set
          // the server version to prevent a DBAL exception (see #1422)
          try {
              $connection = DriverManager::getConnection($params);
              $connection->connect();
              $connection->close();
          } catch (DriverException $e) {
              $extensionConfigs[] = [
                  'dbal' => [
                      'connections' => [
                          'default' => [
                              'server_version' => '5.5',
                          ],
                      ],
                  ],
              ];
          }
  
          return $extensionConfigs;
      }
docs: Adds the database server version to the Doctrine DBAL configuration.
  
  @return array<string,array<string,array<string,array<string,mixed>>>>