`hashlib` add Protocol for hash-objects

Feature or enhancement

hashlib describes a Protocol for hash objects without implementing it.
The proposal is simply to create a concreate Hash or HashObject protocol that makes it explicit.

Pitch

Using the Buffer Protocol (PEP 688) this should look something like

@runtime_checkable
class Hash(Protocol):
    name: str

    def digest_size(self) -> int:
        """Return the size of the hash in bytes."""

    def block_size(self) -> int:
        """Return the internal block size of the hash in bytes."""

    def update(self, data: Buffer) -> None:
        """Update this hash object's state with the provided string."""

    def digest(self) -> bytes:
        """Return the digest value as a string of binary data."""

    def hexdigest(self) -> str:
        """Return the digest value as a string of hexadecimal digits."""

    def copy(self) -> Self:
        """Return a copy ("clone") of the hash object."""

Having a Protocol class instead of prose makes it clear how exactly a hash-function needs to look like.

A second suggestion would be to change hashlib.algorithms_guaranteed and hashlib.algorithms_available from set[str] to dict[str, type[Hash]] objects.

從 hashlib 文件和所參照的 PEP 688 Buffer Protocol 開始，將提議的 Hash 介面與現有的雜湊物件進行比較。確定是否應新增可在執行階段檢查的協定，以及 algorithms_guaranteed 和 algorithms_available 是否應從集合改為對映。完成的標準是：已接受的 API 獲得規格定義並完成實作，同時為支援的雜湊物件提供適當的涵蓋範圍。