Revert "Support SpEL Returning AuthorizationDecision"

This reverts commit 77f2977c55.

docs/modules/ROOT/pages/servlet/authorization/method-security.adoc

@@ -1215,42 +1215,6 @@ Spring Security will invoke the given method on that bean for each method invoca
 What's nice about this is all your authorization logic is in a separate class that can be independently unit tested and verified for correctness.
 It also has access to the full Java language.
 
-[TIP]
-In addition to returning a `Boolean`, you can also return `null` to indicate that the code abstains from making a decision.
-
-If you want to include more information about the nature of the decision, you can instead return a custom `AuthorizationDecision` like this:
-
-[tabs]
-======
-Java::
-+
-[source,java,role="primary"]
-----
-@Component("authz")
-public class AuthorizationLogic {
-    public AuthorizationDecision decide(MethodSecurityExpressionOperations operations) {
-        // ... authorization logic
-        return new MyAuthorizationDecision(false, details);
-    }
-}
-----
-
-Kotlin::
-+
-[source,kotlin,role="secondary"]
-----
-@Component("authz")
-open class AuthorizationLogic {
-    fun decide(val operations: MethodSecurityExpressionOperations): AuthorizationDecision {
-        // ... authorization logic
-        return MyAuthorizationDecision(false, details)
-    }
-}
-----
-======
-
-Then, you can access the custom details when you <<fallback-values-authorization-denied, customize how the authorization result is handled>>.
-
 [[custom-authorization-managers]]
 === Using a Custom Authorization Manager