### 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)

Error err = OK;
	GDScriptParser::FunctionNode *function;
	if (p_is_setter) {
		function = p_variable->setter;
	} else {
		function = p_variable->getter;
	}
	_parse_function(err, p_script, p_class, function);
	return err;
}
Error GDScriptCompiler::_populate_class_members(GDScript *p_script, const GDScriptParser::ClassNode *p_class, bool p_keep_state) {
	if (parsed_classes.has(p_script)) {
		return OK;
	}
	if (parsing_classes.has(p_script)) {
		String class_name = p_class->identifier ? String(p_class->identifier->name) : p_class->fqcn;
		_set_error(vformat(R"(Cyclic class reference for "%s".)", class_name), p_class);
		return ERR_PARSE_ERROR;
	}
	parsing_classes.insert(p_script);
	p_script->clearing = true;
	p_script->native = Ref<GDScriptNativeClass>();
	p_script->base = Ref<GDScript>();
	p_script->_base = nullptr;
	p_script->members.clear();
	
	HashMap<StringName, Variant> constants;
	for (const KeyValue<StringName, Variant> &E : p_script->constants) {