Fix GraalVM native-image support

Spring Boot 3.4.0 native-image fails on Netty, as described in
spring-projects/spring-boot#43273.

This commit actually implements the workaround described in
https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-3.4-Release-Notes#netty-in-native-image.

pom.xml

@@ -130,6 +130,13 @@
             <plugin>
                 <groupId>org.graalvm.buildtools</groupId>
                 <artifactId>native-maven-plugin</artifactId>
+                <configuration>
+                    <!-- Workaround for native image with Netty, as described here: -->
+                    <!-- https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-3.4-Release-Notes#netty-in-native-image -->
+                    <metadataRepository>
+                        <version>0.3.14</version>
+                    </metadataRepository>
+                </configuration>
             </plugin>
             <plugin>
                 <groupId>org.springframework.boot</groupId>