minor #50399 [Security] Add generic to UserProviderInterface (VincentLanglet)

This PR was squashed before being merged into the 6.4 branch.

Discussion
----------

[Security] Add generic to UserProviderInterface

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | no
| New feature?  | yes (but phpdoc only)
| Deprecations? | no
| Tickets       | Fix #... <!-- prefix each issue number with "Fix #", no need to create an issue if none exists, explain below instead -->
| License       | MIT
| Doc PR        | symfony/symfony-docs#... <!-- required for new features -->

Similar to symfony/symfony#48750 `@nicolas`-grekas

Commits
-------

ba46f32d81 Add generic to UserProviderInterface

Author: nicolas-grekas

User/AttributesBasedUserProviderInterface.php

@@ -18,6 +18,10 @@
  * This is particularly useful with self-contained access tokens.
  *
  * @experimental
+ *
+ * @template-covariant TUser of UserInterface
+ *
+ * @template-extends UserProviderInterface<TUser>
  */
 interface AttributesBasedUserProviderInterface extends UserProviderInterface
 {
@@ -26,6 +30,8 @@ interface AttributesBasedUserProviderInterface extends UserProviderInterface
      *
      * This method must throw UserNotFoundException if the user is not found.
      *
+     * @return TUser
+     *
      * @throws UserNotFoundException
      */
     public function loadUserByIdentifier(string $identifier, array $attributes = []): UserInterface;

User/ChainUserProvider.php

@@ -21,6 +21,8 @@
  * handle the request.
  *
  * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ *
+ * @template-implements UserProviderInterface<UserInterface>
  */
 class ChainUserProvider implements UserProviderInterface, PasswordUpgraderInterface
 {

User/InMemoryUserProvider.php

@@ -21,6 +21,8 @@
  * (a backend with a unique admin for instance)
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @template-implements UserProviderInterface<InMemoryUser>
  */
 class InMemoryUserProvider implements UserProviderInterface
 {

User/MissingUserProvider.php

@@ -18,6 +18,8 @@
  * when a firewall requires a user provider but none was defined.
  *
  * @internal
+ *
+ * @template-implements UserProviderInterface<never>
  */
 class MissingUserProvider implements UserProviderInterface
 {

User/UserProviderInterface.php

@@ -28,6 +28,8 @@
  * information is submitted or what the UserInterface object looks like.
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @template-covariant TUser of UserInterface
  */
 interface UserProviderInterface
 {
@@ -41,6 +43,8 @@ interface UserProviderInterface
      *
      * @return UserInterface
      *
+     * @psalm-return TUser
+     *
      * @throws UnsupportedUserException if the user is not supported
      * @throws UserNotFoundException    if the user is not found
      */
@@ -58,6 +62,8 @@ public function supportsClass(string $class);
      *
      * This method must throw UserNotFoundException if the user is not found.
      *
+     * @return TUser
+     *
      * @throws UserNotFoundException
      */
     public function loadUserByIdentifier(string $identifier): UserInterface;