### 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)

_FORCE_INLINE_ Variant *get_global_array() { return _global_array; }
	_FORCE_INLINE_ const HashMap<StringName, int> &get_global_map() const { return globals; }
	_FORCE_INLINE_ const HashMap<StringName, Variant> &get_named_globals_map() const { return named_globals; }
	
	bool has_any_global_constant(const StringName &p_name) { return named_globals.has(p_name) || globals.has(p_name); }
	Variant get_any_global_constant(const StringName &p_name);
	_FORCE_INLINE_ static GDScriptLanguage *get_singleton() { return singleton; }
	virtual String get_name() const override;
	
	virtual void init() override;
	virtual String get_type() const override;
	virtual String get_extension() const override;
	virtual void finish() override;
	
	virtual void get_reserved_words(List<String> *p_words) const override;
	virtual bool is_control_flow_keyword(String p_keywords) const override;
	virtual void get_comment_delimiters(List<String> *p_delimiters) const override;
	virtual void get_string_delimiters(List<String> *p_delimiters) const override;
	virtual bool is_using_templates() override;
	virtual Ref<Script> make_template(const String &p_template, const String &p_class_name, const String &p_base_class_name) const override;
	virtual Vector<ScriptTemplate> get_built_in_templates(StringName p_object) override;
	virtual bool validate(const String &p_script, const String &p_path = "", List<String> *r_functions = nullptr, List<ScriptLanguage::ScriptError> *r_errors = nullptr, List<ScriptLanguage::Warning> *r_warnings = nullptr, HashSet<int> *r_safe_lines = nullptr) const override;
	virtual Script *create_script() const override;
	virtual bool has_named_classes() const override;
	virtual bool supports_builtin_mode() const override;
	virtual bool supports_documentation() const override;
	virtual bool can_inherit_from_file() const override { return true; }