### 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(!fd);
	MutexLock lock(fd->mutex);
	Vector2i size = _get_size(fd, 16);
	ERR_FAIL_COND(!_ensure_cache_for_size(fd, size));
	fd->feature_overrides = p_overrides;
}
Dictionary TextServerFallback::_font_get_opentype_feature_overrides(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->feature_overrides;
}
Dictionary TextServerFallback::_font_supported_feature_list(const RID &p_font_rid) const {
	return Dictionary();
}
Dictionary TextServerFallback::_font_supported_variation_list(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);
	Vector2i size = _get_size(fd, 16);
	ERR_FAIL_COND_V(!_ensure_cache_for_size(fd, size), Dictionary());
	return fd->supported_varaitions;
}
double TextServerFallback::_font_get_global_oversampling() const {