Apply javadoc warnings plugin to aspects

The aspects module currently runs :javadoc as NO-SOURCE because it only contains AspectJ sources. Apply javadoc-warnings-error for consistency with other modules and future Java sources.

Closes gh-18446

Signed-off-by: ddingjoo <ddingsha9@teambind.co.kr>

aspects/spring-security-aspects.gradle

@@ -1,5 +1,6 @@
 apply plugin: 'io.spring.convention.spring-module'
 apply plugin: 'io.freefair.aspectj'
+apply plugin: 'javadoc-warnings-error'
 apply plugin: 'compile-warnings-error'
 
 compileAspectj {