### 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)

virtual int find_function(const String &p_function, const String &p_code) const override;
	virtual String make_function(const String &p_class, const String &p_name, const PackedStringArray &p_args) const override;
	virtual Error complete_code(const String &p_code, const String &p_path, Object *p_owner, List<ScriptLanguage::CodeCompletionOption> *r_options, bool &r_forced, String &r_call_hint) override;
#ifdef TOOLS_ENABLED
	virtual Error lookup_code(const String &p_code, const String &p_symbol, const String &p_path, Object *p_owner, LookupResult &r_result) override;
#endif
	virtual String _get_indentation() const;
	virtual void auto_indent_code(String &p_code, int p_from_line, int p_to_line) const override;
	virtual void add_global_constant(const StringName &p_variable, const Variant &p_value) override;
	virtual void add_named_global_constant(const StringName &p_name, const Variant &p_value) override;
	virtual void remove_named_global_constant(const StringName &p_name) override;
	
	virtual String debug_get_error() const override;
	virtual int debug_get_stack_level_count() const override;
	virtual int debug_get_stack_level_line(int p_level) const override;
	virtual String debug_get_stack_level_function(int p_level) const override;
	virtual String debug_get_stack_level_source(int p_level) const override;
	virtual void debug_get_stack_level_locals(int p_level, List<String> *p_locals, List<Variant> *p_values, int p_max_subitems = -1, int p_max_depth = -1) override;
	virtual void debug_get_stack_level_members(int p_level, List<String> *p_members, List<Variant> *p_values, int p_max_subitems = -1, int p_max_depth = -1) override;
	virtual ScriptInstance *debug_get_stack_level_instance(int p_level) override;
	virtual void debug_get_globals(List<String> *p_globals, List<Variant> *p_values, int p_max_subitems = -1, int p_max_depth = -1) override;
	virtual String debug_parse_stack_level_expression(int p_level, const String &p_expression, int p_max_subitems = -1, int p_max_depth = -1) override;
	virtual void reload_all_scripts() override;
	virtual void reload_tool_script(const Ref<Script> &p_script, bool p_soft_reload) override;
	virtual void frame() override;
	virtual void get_public_functions(List<MethodInfo> *p_functions) const override;
	virtual void get_public_constants(List<Pair<String, Variant>> *p_constants) const override;
	virtual void get_public_annotations(List<MethodInfo> *p_annotations) const override;
	virtual void profiling_start() override;