### 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)

}
	}
#ifdef TOOLS_ENABLED
	
	
	GDScriptDocGen::generate_docs(this, parser.get_tree());
#endif
#ifdef DEBUG_ENABLED
	for (const GDScriptWarning &warning : parser.get_warnings()) {
		if (EngineDebugger::is_active()) {
			Vector<ScriptLanguage::StackInfo> si;
			EngineDebugger::get_script_debugger()->send_error("", get_script_path(), warning.start_line, warning.get_name(), warning.get_message(), false, ERR_HANDLER_WARNING, si);
		}
	}
#endif
	if (can_run) {
		err = _static_init();
		if (err) {
			return err;
		}
	}
#ifdef TOOLS_ENABLED
	if (can_run && p_keep_state) {
		_restore_old_static_data();
	}
#endif
	reloading = false;
	return OK;
}
ScriptLanguage *GDScript::get_language() const {