[Sugerencia] Código Actualizado

Para los que estamos usando la version 3.1.0 de Spring Boot, este codigo funciono para mi:

@Bean
    public SecurityFilterChain securityFilterChain(HttpSecurity httpSecurity) throws Exception {
        return httpSecurity.csrf(AbstractHttpConfigurer::disable)
                .sessionManagement(sess -> sess.sessionCreationPolicy(SessionCreationPolicy.STATELESS))
                .authorizeHttpRequests(auth -> auth.requestMatchers(HttpMethod.POST, "/login").permitAll()
                        .requestMatchers(HttpMethod.DELETE, "/medicos").hasRole("ADMIN")
                        .requestMatchers(HttpMethod.DELETE, "/pacientes").hasRole("ADMIN")
                        .anyRequest().authenticated())
                .addFilterBefore(securityFilter, UsernamePasswordAuthenticationFilter.class)
                .build();
    }