Add missing type hints

[alifeee]

This work should be done in the 6.0.0 release branch

Run mypy --install-types --non-interactive --ignore-missing-imports ./gspread (from CI) to see which types are broken/missing

[bpshaver]

Looking into this. Most of the type errors come from one place.

In utils.py, mypy doesn't like that the named tuple singleton instances are created at the same time as the named tuple class is created.

Dimension = namedtuple("Dimension", ["rows", "cols"])("ROWS", "COLUMNS")

It seems like a better solution for this is a StrEnum. I'll see about making the change and open a PR.

[alifeee]

Hi! Thanks for looking into it!

One thing I forgot to mention in the issue: this work should be done on the 6.0.0 release branch. On this branch, as you suggested, we have already switched to StrEnums.

Also, see the linked PR #1337. I (think that I) fixed the remaining type issues there, and the work is complete. If you are still interested, do have a look. Some things may be patched over with Any that could be done differently, etc.

[bpshaver]

Well drats. I've already made all the necessary changes and was about to open a PR. Serves me right for skimming this issue.

[bpshaver]

Consider #1340 a suggestion. That way you only install strenum if the python version is below 3.11.

[alifeee]

closed by #1337

Well drats. I've already made all the necessary changes and was about to open a PR. Serves me right for skimming this issue.

My bad for not including the branch in the issue description. I should have done this, especially as I tagged this as good first issue