### 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
}
TEST_CASE("[String] Substr") {
	String s = "Killer Baby";
	CHECK(s.substr(3, 4) == "ler ");
	CHECK(s.substr(3) == "ler Baby");
}
TEST_CASE("[String] Find") {
	String s = "Pretty Woman Woman";
	CHECK(s.find("tty") == 3);
	CHECK(s.find("Wo", 9) == 13);
	CHECK(s.find("Revenge of the Monster Truck") == -1);
	CHECK(s.rfind("man") == 15);
}
TEST_CASE("[String] Find no case") {
	String s = "Pretty Whale Whale";
	CHECK(s.findn("WHA") == 7);
	CHECK(s.findn("WHA", 9) == 13);
	CHECK(s.findn("Revenge of the Monster SawFish") == -1);
	CHECK(s.rfindn("WHA") == 13);
}
TEST_CASE("[String] Find MK") {
	Vector<String> keys;
	keys.push_back("sty");
	keys.push_back("tty");
	keys.push_back("man");
	String s = "Pretty Woman";
	int key = 0;
	CHECK(s.findmk(keys, 0, &key) == 3);
	CHECK(key == 1);
	CHECK(s.findmk(keys, 5, &key) == 9);