Suppress warnings for generic types in extension loaders because serv…

…iceloader doesn't return them. Similar to https://github.com/powsybl/powsybl-core/blob/main/commons/src/main/java/com/powsybl/commons/extensions/ExtensionAdderProviders.java

Signed-off-by: BOUHOURS Antoine <[email protected]>

network-store-model/src/main/java/com/powsybl/network/store/model/ExtensionLoaders.java

@@ -18,6 +18,9 @@
 /**
  * @author Antoine Bouhours <antoine.bouhours at rte-france.com>
  */
+//Don't bother with generics because serviceloader doesn't return them
+//and we put them in a cache where we can't propagate the generic types.
+@SuppressWarnings("rawtypes")
 public final class ExtensionLoaders {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(ExtensionLoaders.class);