fix(core): keep web up during graceful shutdown

The `@PreDestroy` hook is triggered very late in the lifecycle.

Started the graceful clean using the global `ShutdownEvent`.

cli/src/main/java/io/kestra/cli/listeners/ShutdownListener.java

@@ -0,0 +1,34 @@
+package io.kestra.cli.listeners;
+
+import io.kestra.worker.DefaultWorker;
+import io.micronaut.context.event.ApplicationEventListener;
+import io.micronaut.context.event.ShutdownEvent;
+import jakarta.inject.Inject;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * Global application shutdown handler.
+ * This handler gets effectively invoked before {@link jakarta.annotation.PreDestroy} does.
+ */
+@Slf4j
+public class ShutdownListener implements ApplicationEventListener<ShutdownEvent> {
+    @Inject
+    DefaultWorker worker;
+
+    /**
+     * {@inheritDoc}
+     **/
+    @Override
+    public void onApplicationEvent(ShutdownEvent event) {
+        log.debug("Shutdown event received");
+        worker.close();
+    }
+
+    /**
+     * {@inheritDoc}
+     **/
+    @Override
+    public boolean supports(ShutdownEvent event) {
+        return ApplicationEventListener.super.supports(event);
+    }
+}