PHP code modernization work. Not finished.

src/Entity/PasswordResetToken.php

@@ -10,7 +10,7 @@ use Doctrine\ORM\Mapping as ORM;
 class PasswordResetToken
 {
     #[ORM\ManyToOne(targetEntity: User::class, fetch: 'EAGER')]
-    #[ORM\JoinColumn(name: '', nullable: false, onDelete: 'CASCADE')]
+    #[ORM\JoinColumn(name: 'user_id', nullable: false, onDelete: 'CASCADE')]
     private User $user;
 
     #[ORM\Id]

src/Entity/User.php

@@ -24,7 +24,7 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
     #[ORM\Column(name: 'password', type: 'text')]
     private string $password;
 
-    #[ORM\Column(name: '', type: 'string', length: 254, unique: true)]
+    #[ORM\Column(name: 'email', type: 'string', length: 254, unique: true)]
     private string $email;
 
     #[ORM\Column(name: 'roles', type: 'json')]
@@ -51,6 +51,12 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
         return $this->id;
     }
 
+    public function getUserIdentifier(): string
+    {
+        return $this->username;
+    }
+
+    /** @deprecated since Symfony 5.3, use getUserIdentifier() instead */
     public function getUsername(): string
     {
         return $this->username;
@@ -66,7 +72,8 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
         $this->password = $hasher->hash($rawPassword);
     }
 
-    public function getSalt()
+    /** @deprecated since Symfony 5.3 */
+    public function getSalt(): ?string
     {
         // Salt is not needed when using Argon2i
         // @see https://symfony.com/doc/current/reference/configuration/security.html#using-the-argon2i-password-encoder
@@ -105,7 +112,7 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
     }
 
     /** @see \Serializable::serialize() */
-    public function serialize()
+    public function serialize(): string
     {
         return serialize([
             $this->id,
@@ -115,7 +122,7 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
     }
 
     /** @see \Serializable::unserialize() */
-    public function unserialize($serialized)
+    public function unserialize($serialized): void
     {
         [
             $this->id,