Revert "Apply Nullability to spring-security-data"

This reverts commit bbcdb236984960416489b4f9d923f83d3a4cba39.

data/spring-security-data.gradle

@@ -1,7 +1,3 @@
-plugins {
-	id 'security-nullability'
-}
-
 apply plugin: 'io.spring.convention.spring-module'
 
 dependencies {

data/src/main/java/org/springframework/security/data/repository/query/SecurityEvaluationContextExtension.java

@@ -29,8 +29,6 @@ import org.springframework.security.core.context.SecurityContext;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.security.core.context.SecurityContextHolderStrategy;
 import org.springframework.util.Assert;
-import org.jspecify.annotations.Nullable;
-import org.jspecify.annotations.NullUnmarked;
 
 /**
  * <p>
@@ -95,7 +93,7 @@ public class SecurityEvaluationContextExtension implements EvaluationContextExte
 	private SecurityContextHolderStrategy securityContextHolderStrategy = SecurityContextHolder
 		.getContextHolderStrategy();
 
-	private @Nullable Authentication authentication;
+	private Authentication authentication;
 
 	private AuthenticationTrustResolver trustResolver = new AuthenticationTrustResolverImpl();
 
@@ -148,7 +146,7 @@ public class SecurityEvaluationContextExtension implements EvaluationContextExte
 		this.securityContextHolderStrategy = securityContextHolderStrategy;
 	}
 
-	private @Nullable Authentication getAuthentication() {
+	private Authentication getAuthentication() {
 		if (this.authentication != null) {
 			return this.authentication;
 		}