This PR was merged into the 4.3 branch.Discussion----------[Lock] mongodb store removed from symfony 4.3MongoDbStore wasn't actually added in symfony 4.3, it will be added in 4.4.Seesymfony/symfony#31889Commits-------75ad033 #27345 Removed Lock MongoDbStore, it will be added in symfony 4.4

This PR was submitted for the 4.4 branch but it was squashed and merged into the 5.1-dev branch instead (closes#31889).Discussion----------[Lock] add mongodb store| Q             | A| ------------- | ---| Branch?       | 4.4| Bug fix?      | no| New feature?  | yes| BC breaks?    | no| Deprecations? | no| Tests pass?   | yes (requires `ext-mongodb` and `mongodb/mongodb` to test)| Fixed tickets |#27345| License       | MIT| Original Doc PR        |symfony/symfony-docs#9807| Remove from 4.3 Doc PR |symfony/symfony-docs#11686| Add to 4.4 Doc PR |symfony/symfony-docs#11735Looks like I messed up `kralos:27345-lock-mongodb` with a force push (trying to fix ci issues) right before it was merged to `master` (`4.3.0`).see#27648**Description**We should support Semaphore Locks with a MongoDB back end to allow those that already use MongoDB as a distributed storage engine.Symfony already partially supports MongoDB for session storage: `Symfony\Component\HttpFoundation\Session\Storage\Handler\MongoDbSessionHandler`**Example**```php$client = new MongoDb\Client();$store = new Symfony\Component\Lock\Store\MongoDbStore(    $client    array(        'database' => 'my-app',    ));$lockFactory = new Symfony\Component\Lock\Factory($store);$lock = $lockFactory->createLock('my-resource');```Commits-------a6bfa59 [Lock] add mongodb store