### 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)

GDScriptCodeGenerator::Address op_result = codegen.add_temporary(_gdtype_from_datatype(assignment->get_datatype(), codegen.script));
					GDScriptCodeGenerator::Address member = codegen.add_temporary(_gdtype_from_datatype(assignment->assignee->get_datatype(), codegen.script));
					gen->write_get_member(member, name);
					gen->write_binary_operator(op_result, assignment->variant_op, member, assigned_value);
					gen->pop_temporary(); 
					to_assign = op_result;
				}
				gen->write_set_member(to_assign, name);
				if (to_assign.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
					gen->pop_temporary(); 
				}
				if (has_operation && assigned_value.mode == GDScriptCodeGenerator::Address::TEMPORARY) {
					gen->pop_temporary(); 
				}
			} else {
				
				ERR_FAIL_COND_V_MSG(assignment->assignee->type != GDScriptParser::Node::IDENTIFIER, GDScriptCodeGenerator::Address(), "Expected the assignee to be an identifier here.");
				GDScriptCodeGenerator::Address member;
				bool is_member = false;
				bool has_setter = false;
				bool is_in_setter = false;
				bool is_static = false;
				GDScriptCodeGenerator::Address static_var_class;
				int static_var_index = 0;
				GDScriptDataType static_var_data_type;
				StringName var_name;
				StringName setter_function;
				var_name = static_cast<const GDScriptParser::IdentifierNode *>(assignment->assignee)->name;
				if (!_is_local_or_parameter(codegen, var_name)) {
					if (codegen.script->member_indices.has(var_name)) {