Update document regarding Stream usage

Signed-off-by: Tran Ngoc Nhan <[email protected]>

Author: ngocnhan-tran1996

docs/modules/ROOT/pages/community.adoc

@@ -21,6 +21,8 @@ We welcome your involvement in the Spring Security project.
 There are many ways to contribute, including answering questions on Stack Overflow, writing new code, improving existing code, assisting with documentation, developing samples or tutorials, reporting bugs, or simply making suggestions.
 For more information, see our https://github.com/spring-projects/spring-security/blob/main/CONTRIBUTING.adoc[Contributing] documentation.
 
+NOTE: Avoid usage of the Stream API for performance reasons. See https://github.com/spring-projects/spring-security/issues/7154[Spring Issue #7154] for more details.
+
 [[community-source]]
 == Source Code