### 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
CHECK(cs == CharString("Test Compare"));
}
TEST_CASE("[String] Comparisons (not equal)") {
	String s = "Test Compare";
	CHECK(s != "Peanut");
	CHECK(s != U"Coconut");
	CHECK(s != L"Coconut");
	CHECK(s != String("Butter"));
}
TEST_CASE("[String] Comparisons (operator <)") {
	String s = "Bees";
	CHECK(s < "Elephant");
	CHECK(!(s < U"Amber"));
	CHECK(!(s < L"Amber"));
	CHECK(!(s < String("Beatrix")));
}
TEST_CASE("[String] Concatenation") {
	String s;
	s += "Have";
	s += ' ';
	s += 'a';
	s += String(" ");
	s = s + U"Nice";
	s = s + " ";
	s = s + String("Day");
	CHECK(s == "Have a Nice Day");
}
TEST_CASE("[String] Testing size and length of string") {
	
	CHECK(String("Mellon").size() == 7);