### 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)

r_ret = const_cast<GDScript *>(this)->callp(E->value.getter, nullptr, 0, ce);
					return true;
				}
				r_ret = top->static_variables[E->value.index];
				return true;
			}
		}
		{
			HashMap<StringName, GDScriptFunction *>::ConstIterator E = top->member_functions.find(p_name);
			if (E && E->value->is_static()) {
				if (top->rpc_config.has(p_name)) {
					r_ret = Callable(memnew(GDScriptRPCCallable(const_cast<GDScript *>(top), E->key)));
				} else {
					r_ret = Callable(const_cast<GDScript *>(top), E->key);
				}
				return true;
			}
		}
		{
			HashMap<StringName, Ref<GDScript>>::ConstIterator E = top->subclasses.find(p_name);
			if (E) {
				r_ret = E->value;
				return true;
			}
		}
		top = top->_base;
	}
	return false;
}
bool GDScript::_set(const StringName &p_name, const Variant &p_value) {