langchain4j#1636 add lombok annotation processor (langchain4j#2105)

## Issue
The JDK23 build is Red 🟥 , because Lombok annotation processor is not
configured as required.

## Change
🟢 The build is green
[Enable Lombok annotation
processor](https://projectlombok.org/setup/maven) to make the build
green under JDK23


## General checklist
- [x] There are no breaking changes
- [ ] I have added unit and integration tests for my change
- [ ] I have manually run all the unit and integration tests in the
module I have added/changed, and they are all green
- [ ] I have manually run all the unit and integration tests in the
[core](https://github.com/langchain4j/langchain4j/tree/main/langchain4j-core)
and
[main](https://github.com/langchain4j/langchain4j/tree/main/langchain4j)
modules, and they are all green
- [ ] I have added/updated the
[documentation](https://github.com/langchain4j/langchain4j/tree/main/docs/docs)
- [ ] I have added an example in the [examples
repo](https://github.com/langchain4j/langchain4j-examples) (only for
"big" features)
- [ ] I have added/updated [Spring Boot
starter(s)](https://github.com/langchain4j/langchain4j-spring) (if
applicable)

langchain4j-parent/pom.xml

@@ -390,6 +390,16 @@
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-compiler-plugin</artifactId>
                     <version>3.13.0</version>
+                    <configuration>
+                        <annotationProcessorPaths>
+                            <path>
+                                <!-- todo: Remove when Lombok is eliminated everywhere https://github.com/langchain4j/langchain4j/issues/1636 -->
+                                <groupId>org.projectlombok</groupId>
+                                <artifactId>lombok</artifactId>
+                                <version>${lombok.version}</version>
+                            </path>
+                        </annotationProcessorPaths>
+                    </configuration>
                 </plugin>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>