Remove unnecessary lambda blocks

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

Issue gh-8945

web/src/main/java/org/springframework/security/web/server/header/StaticServerHttpHeadersWriter.java

@@ -43,9 +43,7 @@ public class StaticServerHttpHeadersWriter implements ServerHttpHeadersWriter {
 		HttpHeaders headers = exchange.getResponse().getHeaders();
 		boolean containsOneHeaderToAdd = Collections.disjoint(headers.keySet(), this.headersToAdd.keySet());
 		if (containsOneHeaderToAdd) {
-			this.headersToAdd.forEach((name, values) -> {
-				headers.put(name, values);
-			});
+			this.headersToAdd.forEach(headers::put);
 		}
 		return Mono.empty();
 	}

web/src/test/java/org/springframework/security/web/method/annotation/CurrentSecurityContextArgumentResolverTests.java

@@ -111,9 +111,8 @@ public class CurrentSecurityContextArgumentResolverTests {
 		SecurityContext context = SecurityContextHolder.getContext();
 		Authentication authentication = context.getAuthentication();
 		context.setAuthentication(null);
-		assertThatExceptionOfType(SpelEvaluationException.class).isThrownBy(() -> {
-			this.resolver.resolveArgument(showSecurityContextAuthenticationWithPrincipal(), null, null, null);
-		});
+		assertThatExceptionOfType(SpelEvaluationException.class).isThrownBy(() -> this.resolver
+				.resolveArgument(showSecurityContextAuthenticationWithPrincipal(), null, null, null));
 		context.setAuthentication(authentication);
 	}