Fix issue with Gradle 8.6 and catalog access (projects without catalog)

In earlier version, in a standard configuration, if the
'VersionCatalogsExtension' existed, there was also a catalog called
'libs'. If there were no catalog at all, the extension did not
exist. This has changed recently. This causes the plugin to fail
in a standard setup where the catalog is NOT used.

Author: jjohannes

src/main/java/org/gradlex/javamodule/dependencies/JavaModuleDependenciesExtension.java

@@ -266,7 +266,7 @@ public Provider<Map<String, Object>> gav(Provider<String> moduleName) {
     }
 
     private Map<String, Object> findGav(String ga, String moduleName) {
-        VersionCatalog catalog = versionCatalogs == null ? null : versionCatalogs.named(getVersionCatalogName().get());
+        VersionCatalog catalog = versionCatalogs == null ? null : versionCatalogs.find(getVersionCatalogName().get()).orElse(null);
         Optional<VersionConstraint> version = catalog == null ? empty() : catalog.findVersion(moduleName.replace('_', '.'));
         Map<String, Object> gav = new HashMap<>();
         String[] gaSplit = ga.split(":");