dependencies {
  // необходимые
    implementation 'org.springframework.boot:spring-boot-starter-security'
    implementation 'org.springframework.boot:spring-boot-starter-web'
      
  // для красоты, удобства и тестов
    compileOnly 'org.projectlombok:lombok'
    developmentOnly 'org.springframework.boot:spring-boot-devtools'
    annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
    annotationProcessor 'org.projectlombok:lombok'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
    testImplementation 'org.springframework.security:spring-security-test'
}

@Retention(RetentionPolicy.RUNTIME) 
@Target({ElementType.TYPE}) 
@Documented 
@Import({org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration.class,org.springframework.security.config.annotation.web.configuration.SpringWebMvcImportSelector.class,org.springframework.security.config.annotation.web.configuration.OAuth2ImportSelector.class,org.springframework.security.config.annotation.web.configuration.HttpSecurityConfiguration.class}) 
@EnableGlobalAuthentication 
@Configuration 
public @interface EnableWebSecurity
extends annotation.Annotation

org.springframework.security.web.authentication.       AnonymousAuthenticationFilter
org.springframework.security.web.csrf.                 CsrfFilter
org.springframework.security.web.session.              DisableEncodeUrlFilter
org.springframework.security.web.access.               ExceptionTranslationFilter
org.springframework.security.web.header.               HeaderWriterFilter
org.springframework.security.web.authentication.logout.LogoutFilter
org.springframework.security.web.savedrequest.         RequestCacheAwareFilter
org.springframework.security.web.servletapi.           SecurityContextHolderAwareRequestFilter
org.springframework.security.web.context.              SecurityContextPersistenceFilter
org.springframework.security.web.session.              SessionManagementFilter
org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter

import lombok.val;
import org.springframework.context.annotation.Bean;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
import org.springframework.security.web.SecurityFilterChain;

@EnableWebSecurity
public class SecurityFilterChainImpl {
    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        return chain = http
                .anonymous(AbstractHttpConfigurer::disable)         // AnonymousAuthenticationFilter
                .csrf(AbstractHttpConfigurer::disable)              // CsrfFilter
                .sessionManagement(AbstractHttpConfigurer::disable) // DisableEncodeUrlFilter, SessionManagementFilter
                .exceptionHandling(AbstractHttpConfigurer::disable) // ExceptionTranslationFilter
                .headers(AbstractHttpConfigurer::disable)           // HeaderWriterFilter
                .logout(AbstractHttpConfigurer::disable)            // LogoutFilter
                .requestCache(AbstractHttpConfigurer::disable)      // RequestCacheAwareFilter
                .servletApi(AbstractHttpConfigurer::disable)        // SecurityContextHolderAwareRequestFilter
                .securityContext(AbstractHttpConfigurer::disable)   // SecurityContextPersistenceFilter
                .build();
    }
}

Выключить можно и устаревшим (как выражается документация Спринга: без лямбд, ведь это менее удобно) вызовом: .anonymous().disable().and()

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Controller {

    @GetMapping
    public String get() {
        return "Hello!";
    }
}

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

import static org.junit.jupiter.api.Assertions.assertEquals;

@SpringBootTest
public class ControllerIT {

    @Test
    public void test() throws IOException, InterruptedException {
        final HttpRequest request = HttpRequest.newBuilder()
                .uri(URI.create("http://localhost:8080"))
                .GET()
                .build();
        final HttpClient client = HttpClient.newHttpClient();

        final HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

        assertEquals("Hello!", response.body());
    }
}