### 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)

return script;
}
ScriptLanguage *GDScriptInstance::get_language() {
	return GDScriptLanguage::get_singleton();
}
const Variant GDScriptInstance::get_rpc_config() const {
	return script->get_rpc_config();
}
void GDScriptInstance::reload_members() {
#ifdef DEBUG_ENABLED
	Vector<Variant> new_members;
	new_members.resize(script->member_indices.size());
	
	for (KeyValue<StringName, GDScript::MemberInfo> &E : script->member_indices) {
		if (member_indices_cache.has(E.key)) {
			Variant value = members[member_indices_cache[E.key]];
			new_members.write[E.value.index] = value;
		}
	}
	members.resize(new_members.size()); 
	
	members = new_members;
	
	member_indices_cache.clear();
	for (const KeyValue<StringName, GDScript::MemberInfo> &E : script->member_indices) {
		member_indices_cache[E.key] = E.value.index;
	}
#endif
}
GDScriptInstance::GDScriptInstance() {