fix: add junit-jupiter-api dependency to immutable module #3448

Required for @test annotations and assert methods in test code.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: alex052525

immutable/pom.xml

@@ -47,6 +47,12 @@
       <artifactId>junit-jupiter-engine</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <version>${junit.version}</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
   <build>
     <plugins>