Add .gitignore to avoid tracking python-generated files

[theStack]

Avoids tracking pre-compiled python files that are created in the course of running the tests or examples for the first time, e.g. on master:

$ ./python/tests.sh && git status
On branch master
Your branch is up to date with 'origin/master'.

Untracked files:
  (use "git add <file>..." to include in what will be committed)
        python/__pycache__/
        python/chilldkg_ref/__pycache__/
        python/secp256k1lab/__pycache__/

nothing added to commit but untracked files present (use "git add" to track)

[real-or-random]

Perhaps just add https://github.com/github/gitignore/blob/main/Python.gitignore, or better, a hand-picked selection of the sections in this file?

[theStack]

Perhaps just add https://github.com/github/gitignore/blob/main/Python.gitignore, or better, a hand-picked selection of the sections in this file?

Didn't pick by hand, but used the one that uv creates by default as a starting point:

$ uv --version
uv 0.6.6
$ uv init test_project
Initialized project `test-project` at `/home/thestack/test_project`
$ cat test_project/.gitignore
# Python-generated files
__pycache__/
*.py[oc]
build/
dist/
wheels/
*.egg-info

# Virtual environments
.venv

Not sure if they are all relevant for us, as bip-frost-dkg itself is not a python package though. Happy to take suggestions.