fix: allow usage on ctor

(cherry picked from commit 9842ded)

util/src/main/java/io/camunda/zeebe/util/VisibleForTesting.java

@@ -21,7 +21,7 @@
  * comprehensive tests. In general, you should try to avoid this, but at times there is no other
  * way.
  */
-@Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD})
+@Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD, ElementType.CONSTRUCTOR})
 @Retention(RetentionPolicy.SOURCE)
 @Documented
 public @interface VisibleForTesting {}