### 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)

prop_info.type = export_info.type;
						prop_info.class_name = export_info.class_name;
					}
					prop_info.hint = export_info.hint;
					prop_info.hint_string = export_info.hint_string;
					prop_info.usage = export_info.usage;
				}
				prop_info.usage |= PROPERTY_USAGE_SCRIPT_VARIABLE;
				minfo.property_info = prop_info;
				if (variable->is_static) {
					minfo.index = p_script->static_variables_indices.size();
					p_script->static_variables_indices[name] = minfo;
				} else {
					minfo.index = p_script->member_indices.size();
					p_script->member_indices[name] = minfo;
					p_script->members.insert(name);
				}
#ifdef TOOLS_ENABLED
				if (variable->initializer != nullptr && variable->initializer->is_constant) {
					p_script->member_default_values[name] = variable->initializer->reduced_value;
					GDScriptCompiler::convert_to_initializer_type(p_script->member_default_values[name], variable);
				} else {
					p_script->member_default_values.erase(name);
				}
#endif
			} break;
			case GDScriptParser::ClassNode::Member::CONSTANT: {
				const GDScriptParser::ConstantNode *constant = member.constant;
				StringName name = constant->identifier->name;
				p_script->constants.insert(name, constant->initializer->reduced_value);