deinit

pub fn deinit(self: *Cache, gpa: std.mem.Allocator, backend: dvui.Backend) void {
        defer self.* = undefined;
        var it = self.cache.iterator();
        while (it.next()) |item| {
            backend.textureDestroy(item.value_ptr.*);
        }
        self.cache.deinit(gpa);
        for (self.trash.items) |tex| {
            backend.textureDestroy(tex);
        }
        self.trash.deinit(gpa);

        for (self.trash_target.items) |tex| {
            backend.textureDestroyTarget(tex);
        }
        self.trash_target.deinit(gpa);
    }