[JAVA-32669] Move article out of core-java-collections-5 (#16327)

core-java-modules/core-java-collections-5/README.md

@@ -9,7 +9,6 @@
 - [Skipping the First Iteration in Java](https://www.baeldung.com/java-skip-first-iteration)
 - [Remove Elements From a Queue Using Loop](https://www.baeldung.com/java-remove-elements-queue)
 - [Intro to Vector Class in Java](https://www.baeldung.com/java-vector-guide)
-- [HashSet toArray() Method in Java](https://www.baeldung.com/java-hashset-toarray)
 - [Time Complexity of Java Collections Sort in Java](https://www.baeldung.com/java-time-complexity-collections-sort)
 - [Check if List Contains at Least One Enum](https://www.baeldung.com/java-list-check-enum-presence)
 - [Comparison of for Loops and Iterators](https://www.baeldung.com/java-for-loops-vs-iterators)

core-java-modules/core-java-collections-5/pom.xml

@@ -55,8 +55,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>9</source>
+                    <source>16</source>
-                    <target>9</target>
+                    <target>16</target>
                 </configuration>
             </plugin>
         </plugins>

core-java-modules/core-java-collections-conversions-3/README.md

@@ -5,3 +5,4 @@ This module contains articles about conversions among Collection types in Java.
 ### Relevant Articles:
 - [Converting HashMap Values to an ArrayList in Java](https://www.baeldung.com/java-hashmap-arraylist)
 - [Joining a List<String> in Java With Commas and “and”](https://www.baeldung.com/java-string-concatenation-natural-language)
+- [HashSet toArray() Method in Java](https://www.baeldung.com/java-hashset-toarray)