Avoid using autogenerated project name with docker compose plugin (elastic#93015)

The docker-compose plugin uses randomized auto-generated project names
for test fixtures. This can cause issues on some platforms where it will
generate an invalid identifier. This commit simply configures the plugin
to use the gradle project name for docker compose.

Author: mark-vieira

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/testfixtures/TestFixturesPlugin.java

@@ -117,6 +117,7 @@ public void execute(Task task) {
             maybeSkipTask(dockerSupport, buildFixture);
 
             ComposeExtension composeExtension = project.getExtensions().getByType(ComposeExtension.class);
+            composeExtension.setProjectName(project.getName());
             composeExtension.getUseComposeFiles().addAll(Collections.singletonList(DOCKER_COMPOSE_YML));
             composeExtension.getRemoveContainers().set(true);
             composeExtension.getCaptureContainersOutput()