### Godot version

4.1.1

### System information

linux

### Issue description

The `"%+f"` format adds a `+` sign in front of positive numbers. If you try to format `-0.0`, it breaks and displays both a `+` and a `-`.

### Steps to reproduce

```gdscript
@tool
extends EditorScript

func _run() -> void:
    print("%+f" % -0.0)
```

### Minimal reproduction project

see above
args.push_back(3);
	args.push_back(99.99);
	output = format.sprintf(args, &error);
	REQUIRE(error == false);
	CHECK(output == String("fish     99.990 frog"));
	
	
	format = "fish %s %s frog";
	args.clear();
	args.push_back("cheese");
	output = format.sprintf(args, &error);
	REQUIRE(error);
	CHECK(output == "not enough arguments for format string");
	
	format = "fish %s frog";
	args.clear();
	args.push_back("hello");
	args.push_back("cheese");
	output = format.sprintf(args, &error);
	REQUIRE(error);
	CHECK(output == "not all arguments converted during string formatting");
	
	format = "fish %10";
	args.clear();
	args.push_back("cheese");
	output = format.sprintf(args, &error);
	REQUIRE(error);
	CHECK(output == "incomplete format");
	
	format = "fish %&f frog";