### Godot version

4.0 dev Beta 10

### System information

MacBook Pro M1 Max

### Issue description

After I imported font.ttf file and move it from one folder to another under ://res godot suddenly crashed, and it still crashes after restart.

### Steps to reproduce

Import some font.ttf file and try to move into different folder

### Minimal reproduction project

N/A
FontFallback *fd = font_owner.get_or_null(p_font_rid);
	ERR_FAIL_COND_V(!fd, Transform2D());
	MutexLock lock(fd->mutex);
	return fd->transform;
}
void TextServerFallback::_font_set_variation_coordinates(const RID &p_font_rid, const Dictionary &p_variation_coordinates) {
	FontFallback *fd = font_owner.get_or_null(p_font_rid);
	ERR_FAIL_COND(!fd);
	MutexLock lock(fd->mutex);
	if (fd->variation_coordinates != p_variation_coordinates) {
		_font_clear_cache(fd);
		fd->variation_coordinates = p_variation_coordinates;
	}
}
Dictionary TextServerFallback::_font_get_variation_coordinates(const RID &p_font_rid) const {
	FontFallback *fd = font_owner.get_or_null(p_font_rid);
	ERR_FAIL_COND_V(!fd, Dictionary());
	MutexLock lock(fd->mutex);
	return fd->variation_coordinates;
}
void TextServerFallback::_font_set_oversampling(const RID &p_font_rid, double p_oversampling) {
	FontFallback *fd = font_owner.get_or_null(p_font_rid);
	ERR_FAIL_COND(!fd);
	MutexLock lock(fd->mutex);
	if (fd->oversampling != p_oversampling) {
		_font_clear_cache(fd);
		fd->oversampling = p_oversampling;
	}
}
double TextServerFallback::_font_get_oversampling(const RID &p_font_rid) const {