### 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
format = "fish %+f frog";
	args.clear();
	args.push_back(99.99);
	output = format.sprintf(args, &error);
	REQUIRE(error == false);
	CHECK(output == String("fish +99.990000 frog"));
	
	format = "fish %.1f frog";
	args.clear();
	args.push_back(99.99);
	output = format.sprintf(args, &error);
	REQUIRE(error == false);
	CHECK(output == String("fish 100.0 frog"));
	
	format = "fish %.12f frog";
	args.clear();
	args.push_back(99.99);
	output = format.sprintf(args, &error);
	REQUIRE(error == false);
	CHECK(output == String("fish 99.990000000000 frog"));
	
	format = "fish %.f frog";
	args.clear();
	args.push_back(99.99);
	output = format.sprintf(args, &error);
	REQUIRE(error == false);
	CHECK(output == String("fish 100 frog"));
	
	format = "fish %-011f frog";