### 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
setter(&s, 1, &v, &oob);
	CHECK_FALSE(oob);
	CHECK_EQ(s, String("azcd"));
}
TEST_CASE("[String] Variant ptr indexed set") {
	String s("abcd");
	Variant::PTRIndexedSetter setter = Variant::get_member_ptr_indexed_setter(Variant::STRING);
	String v("z");
	setter(&s, 1, &v);
	CHECK_EQ(s, String("azcd"));
}
TEST_CASE("[Stress][String] Empty via ' == String()'") {
	for (int i = 0; i < 100000; ++i) {
		String str = "Hello World!";
		if (str == String()) {
			continue;
		}
	}
}
TEST_CASE("[Stress][String] Empty via `is_empty()`") {
	for (int i = 0; i < 100000; ++i) {
		String str = "Hello World!";
		if (str.is_empty()) {
			continue;
		}
	}
}
} // namespace TestString
#endif // TEST_STRING_H