minor #16990 [Security] Update custom_authenticator (mohamedGasmii)

This PR was merged into the 6.0 branch.

Discussion
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[Security] Update custom_authenticator

Adjust authenticate() return type & createToken $passport typehint to be like the definition in AuthenticatorInterface

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Commits
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4f152cd [Security] Update custom_authenticator

Author: javiereguiluz

security/custom_authenticator.rst

@@ -355,7 +355,7 @@ authenticator methods (e.g. ``createToken()``)::
     {
         // ...
 
-        public function authenticate(Request $request): PassportInterface
+        public function authenticate(Request $request): Passport
         {
             // ... process the request
 
@@ -367,7 +367,7 @@ authenticator methods (e.g. ``createToken()``)::
             return $passport;
         }
 
-        public function createToken(PassportInterface $passport, string $firewallName): TokenInterface
+        public function createToken(Passport $passport, string $firewallName): TokenInterface
         {
             // read the attribute value
             return new CustomOauthToken($passport->getUser(), $passport->getAttribute('scope'));