### 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)

GDScriptFunction *initializer = nullptr; 
	GDScriptFunction *implicit_ready = nullptr;
	GDScriptFunction *static_initializer = nullptr;
	Error _static_init();
	int subclass_count = 0;
	RBSet<Object *> instances;
	bool destructing = false;
	bool clearing = false;
	
	String source;
	String path;
	StringName local_name; 
	StringName global_name; 
	String fully_qualified_name;
	String simplified_icon_path;
	SelfList<GDScript> script_list;
	SelfList<GDScriptFunctionState>::List pending_func_states;
	GDScriptFunction *_super_constructor(GDScript *p_script);
	void _super_implicit_constructor(GDScript *p_script, GDScriptInstance *p_instance, Callable::CallError &r_error);
	GDScriptInstance *_create_instance(const Variant **p_args, int p_argcount, Object *p_owner, bool p_is_ref_counted, Callable::CallError &r_error);
	String _get_debug_path() const;
#ifdef TOOLS_ENABLED
	HashSet<PlaceHolderScriptInstance *> placeholders;
	
	virtual void _placeholder_erased(PlaceHolderScriptInstance *p_placeholder) override;
#endif
#ifdef DEBUG_ENABLED
	HashMap<ObjectID, List<Pair<StringName, Variant>>> pending_reload_state;
#endif
	bool _update_exports(bool *r_err = nullptr, bool p_recursive_call = false, PlaceHolderScriptInstance *p_instance_to_update = nullptr);