Create `.gitignore` file in `scoop` directory

[bersbersbers]

Description

Some people (read, me) use a scoop installation in a git working copy - e.g., to be able to cache it in GitLab CI, which can only cache files relative to the git repository and not outside of it. However, git operations should probably not consider this directory.

Possible Solution

Create a .gitignore file containing only *, compare https://github.com/python/cpython/pull/108125