Remove unnecessary lambda blocks

Remove lambda blocks that aren't needed and replace instead with a
simple expression.

Issue gh-8945

core/src/test/java/org/springframework/security/jackson2/SecurityJackson2ModulesTests.java

@@ -51,9 +51,7 @@ public class SecurityJackson2ModulesTests {
 	@Test
 	public void readValueWhenNotAllowedOrMappedThenThrowsException() {
 		String content = "{\"@class\":\"org.springframework.security.jackson2.SecurityJackson2ModulesTests$NotAllowlisted\",\"property\":\"bar\"}";
-		assertThatThrownBy(() -> {
-			this.mapper.readValue(content, Object.class);
-		}).hasStackTraceContaining("allowlist");
+		assertThatThrownBy(() -> this.mapper.readValue(content, Object.class)).hasStackTraceContaining("allowlist");
 	}
 
 	@Test