Note in GitCmdObjectDB should be removed or updated

[EliahKagan]

Somewhat similar to #1845, the git.db.GitCmdObjectDB docstring contains this note:

GitPython/git/db.py

Lines 34 to 35 in 87b8035

	:note: For now, we use the git command to do all the lookup, just until we
	have packs and the other implementations.

I think that note can simply be removed now, since as far as I know, it does not correspond to a current goal and is not needed to understand the code or how to use it. But I am not confident of this, because I am not sure exactly what it is actually referring to. If more features were implemented, would this have been:

• A change to GitCmdObjectDB itself?
• Switching back from GitCmdObjectDB to GitDB?
• A combination of the two, or something else related?

That only needs to be answered if it affects what should happen in that docstring (or elsewhere), which is why I've made this an issue rather than a discussion question.

I plan to remove it in a forthcoming PR with a number of other docstring revisions, but I'm opening this in case my understanding is mistaken.

[Byron]

Thank you for sharing your findings!

That note was definitely referring to having a built-in implementation of the Git Object Database, which never manifested, and what was there was obviously too slow.

Thus, I think it's absolutely fair to remove the note.