Add support for passing in label kwargs to remove() function

Hello,

Would it be possible/would it get maintainer support to add the ability to pass in kwargs to the remove() function:
https://github.com/prometheus/client_python/blob/5a5261dd45d65914b5e3d8225b94d6e0578882f3/prometheus_client/metrics.py#L200

I think it should be pretty simple to do, I think the logic would remain largely the same as the above labels() function from an implementation perspective, but rather than setting a value it just calls del on it.

Thanks!

从 prometheus_client/metrics.py 中所引用的 remove() 函数附近开始，并将其与 labels() 函数进行比较。在保留现有行为的同时，添加通过 label kwargs 进行删除的支持，然后运行相关的项目测试，并确认两种删除方式都能正确运行。