### 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)

if (src_address.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
						codegen.generator->pop_temporary();
					}
					initialized = true;
				} else if (local_type.has_type) {
					
					if (local_type.has_container_element_type()) {
						codegen.generator->write_construct_typed_array(local, local_type.get_container_element_type(), Vector<GDScriptCodeGenerator::Address>());
						initialized = true;
					} else if (local_type.kind == GDScriptDataType::BUILTIN) {
						codegen.generator->write_construct(local, local_type.builtin_type, Vector<GDScriptCodeGenerator::Address>());
						initialized = true;
					}
					
				}
				
				if (!initialized && p_block->is_in_loop) {
					codegen.generator->write_construct(local, Variant::NIL, Vector<GDScriptCodeGenerator::Address>());
				}
			} break;
			case GDScriptParser::Node::CONSTANT: {
				
				const GDScriptParser::ConstantNode *lc = static_cast<const GDScriptParser::ConstantNode *>(s);
				if (!lc->initializer->is_constant) {
					_set_error("Local constant must have a constant value as initializer.", lc->initializer);
					return ERR_PARSE_ERROR;
				}
				codegen.add_local_constant(lc->identifier->name, lc->initializer->reduced_value);
			} break;
			case GDScriptParser::Node::PASS: