### 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)

p_script->implicit_ready = nullptr;
	p_script->static_initializer = nullptr;
	p_script->clearing = false;
	p_script->tool = parser->is_tool();
	if (p_script->local_name != StringName()) {
		if (ClassDB::class_exists(p_script->local_name) && ClassDB::is_class_exposed(p_script->local_name)) {
			_set_error(vformat(R"(The class "%s" shadows a native class)", p_script->local_name), p_class);
			return ERR_ALREADY_EXISTS;
		}
	}
	GDScriptDataType base_type = _gdtype_from_datatype(p_class->base_type, p_script);
	int native_idx = GDScriptLanguage::get_singleton()->get_global_map()[base_type.native_type];
	p_script->native = GDScriptLanguage::get_singleton()->get_global_array()[native_idx];
	ERR_FAIL_COND_V(p_script->native.is_null(), ERR_BUG);
	
	switch (base_type.kind) {
		case GDScriptDataType::NATIVE:
			
			break;
		case GDScriptDataType::GDSCRIPT: {
			Ref<GDScript> base = Ref<GDScript>(base_type.script_type);
			if (base.is_null()) {
				return ERR_COMPILATION_FAILED;
			}
			if (main_script->has_class(base.ptr())) {
				Error err = _populate_class_members(base.ptr(), p_class->base_type.class_type, p_keep_state);
				if (err) {
					return err;
				}
			} else if (!base->is_valid()) {