### 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)

Error err = OK;
	GDScriptCodeGenerator *gen = codegen.generator;
	List<GDScriptCodeGenerator::Address> block_locals;
	gen->clean_temporaries();
	codegen.start_block();
	if (p_add_locals) {
		block_locals = _add_locals_in_block(codegen, p_block);
	}
	for (int i = 0; i < p_block->statements.size(); i++) {
		const GDScriptParser::Node *s = p_block->statements[i];
#ifdef DEBUG_ENABLED
		
		gen->write_newline(s->start_line);
#endif
		switch (s->type) {
			case GDScriptParser::Node::MATCH: {
				const GDScriptParser::MatchNode *match = static_cast<const GDScriptParser::MatchNode *>(s);
				codegen.start_block();
				
				GDScriptCodeGenerator::Address value = codegen.add_local("@match_value", _gdtype_from_datatype(match->test->get_datatype(), codegen.script));
				GDScriptCodeGenerator::Address value_expr = _parse_expression(codegen, err, match->test);
				if (err) {
					return err;
				}
				
				
				gen->write_assign(value, value_expr);
				if (value_expr.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
					codegen.generator->pop_temporary();