### 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
String input = test_cases[idx].input;
		CHECK(input.to_camel_case() == test_cases[idx].camel_case);
		CHECK(input.to_pascal_case() == test_cases[idx].pascal_case);
		CHECK(input.to_snake_case() == test_cases[idx].snake_case);
		idx++;
	}
}
TEST_CASE("[String] Checking string is empty when it should be") {
	bool state = true;
	bool success;
	String a = "";
	success = a[0] == 0;
	if (!success) {
		state = false;
	}
	String b = "Godot";
	success = b[b.size()] == 0;
	if (!success) {
		state = false;
	}
	const String c = "";
	success = c[0] == 0;
	if (!success) {
		state = false;
	}
	const String d = "Godot";
	success = d[d.size()] == 0;
	if (!success) {
		state = false;
	}