minor #18197 Patch 17 (hbgamra)

This PR was submitted for the 6.3 branch but it was merged into the 5.4 branch instead.

Discussion
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Patch 17

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Commits
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2ea62fa Update user_providers.rst

Author: OskarStark

security/user_providers.rst

@@ -328,7 +328,7 @@ command will generate a nice skeleton to get you started::
          *
          * @return UserInterface
          */
-        public function refreshUser(UserInterface $user)
+        public function refreshUser(UserInterface $user): UserInterface
         {
             if (!$user instanceof User) {
                 throw new UnsupportedUserException(sprintf('Invalid user class "%s".', get_class($user)));
@@ -342,7 +342,7 @@ command will generate a nice skeleton to get you started::
         /**
          * Tells Symfony to use this provider for this User class.
          */
-        public function supportsClass(string $class)
+        public function supportsClass(string $class): bool
         {
             return User::class === $class || is_subclass_of($class, User::class);
         }