### Godot version

3fa8fad

### System information

Debian Linux x86

### Issue description

#79205 introduces a regression to the way rpc configs are inherited, causing this error:

```
ERROR: Unable to get the RPC configuration for the function "foo" at path: "/root/Node". This happens when the method is missing or not marked for RPCs in the local script.
```

even though the function exists both in the server and the client. If you `print(self.foo)`, it even tells you that it's rpc: `Node(client.gd)::foo (rpc)` 

Before #79205 `GdScriptCompiler::_populate_class_members` used `GDScriptCache::get_full_script` to access the base script. This causes the parent script to be compiled (if it is not compiled yet), which in turn initializes the `rpc_config` property with a copy of the base value in [gdscript.cpp::_init_rpc_methods_properties](https://github.com/godotengine/godot/blob/3fa8fad26b97a8af20e7996b7e17d8f23fc04b89/modules/gdscript/gdscript.cpp#L1398-L1412)

However, `GDScriptCache::get_shallow_script` does not compile and thus does not initialize the `rpc_config` of the base script, causing the rpc functions not being included in the rpc config.

### Steps to reproduce

Extend a gdscript with a `@rpc` function annotation and try to do a network call:

server.gd:
```gdscript
extends Node

func _ready():
	var peer := ENetMultiplayerPeer.new()
	peer.create_server(1337)
	multiplayer.multiplayer_peer = peer

@rpc("any_peer") func foo():
	print("Server")
```

parent.gd:
```gdscript
extends Node

@rpc func foo(): pass
```

client.gd:
```gdscript
extends "parent.gd"

func _ready():
	var peer := ENetMultiplayerPeer.new()
	peer.create_client("localhost", 1337)
	multiplayer.connected_to_server.connect(func (): self.foo.rpc_id(1))
	multiplayer.multiplayer_peer = peer
```


### Minimal reproduction project

[test.zip](https://github.com/godotengine/godot/files/12215814/test.zip)

}
	}
	for (KeyValue<Ref<GDScript>, HashMap<ObjectID, List<Pair<StringName, Variant>>>> &E : to_reload) {
		Ref<GDScript> scr = E.key;
		scr->reload(p_soft_reload);
		
		for (KeyValue<ObjectID, List<Pair<StringName, Variant>>> &F : E.value) {
			List<Pair<StringName, Variant>> &saved_state = F.value;
			Object *obj = ObjectDB::get_instance(F.key);
			if (!obj) {
				continue;
			}
			if (!p_soft_reload) {
				
				obj->set_script(Variant());
			}
			obj->set_script(scr);
			ScriptInstance *script_inst = obj->get_script_instance();
			if (!script_inst) {
				
				if (!scr->pending_reload_state.has(obj->get_instance_id())) {
					scr->pending_reload_state[obj->get_instance_id()] = saved_state;
				}
				continue;
			}
			if (script_inst->is_placeholder() && scr->is_placeholder_fallback_enabled()) {
				PlaceHolderScriptInstance *placeholder = static_cast<PlaceHolderScriptInstance *>(script_inst);
				for (List<Pair<StringName, Variant>>::Element *G = saved_state.front(); G; G = G->next()) {
					placeholder->property_set_fallback(G->get().first, G->get().second);
				}