### 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)

switch (member.type) {
			case GDScriptParser::ClassNode::Member::VARIABLE: {
				const GDScriptParser::VariableNode *variable = member.variable;
				StringName name = variable->identifier->name;
				GDScript::MemberInfo minfo;
				switch (variable->property) {
					case GDScriptParser::VariableNode::PROP_NONE:
						break; 
					case GDScriptParser::VariableNode::PROP_SETGET:
						if (variable->setter_pointer != nullptr) {
							minfo.setter = variable->setter_pointer->name;
						}
						if (variable->getter_pointer != nullptr) {
							minfo.getter = variable->getter_pointer->name;
						}
						break;
					case GDScriptParser::VariableNode::PROP_INLINE:
						if (variable->setter != nullptr) {
							minfo.setter = "@" + variable->identifier->name + "_setter";
						}
						if (variable->getter != nullptr) {
							minfo.getter = "@" + variable->identifier->name + "_getter";
						}
						break;
				}
				minfo.data_type = _gdtype_from_datatype(variable->get_datatype(), p_script);
				PropertyInfo prop_info = variable->get_datatype().to_property_info(name);
				PropertyInfo export_info = variable->export_info;
				if (variable->exported) {
					if (!minfo.data_type.has_type) {