Migrate from backoff to backon - drop-in replacement, archived upstream

[Llucs]

Is your feature request related to a problem? Please describe.

The backoff library (litl/backoff) was archived in August 2025 and is no longer maintained. It is also incompatible with Python 3.14+ due to the removal of the deprecated asyncio.iscoroutinefunction() API.

howfairis currently depends on backoff==2.2.* and uses it in 3 files under howfairis/requesting/:

• get_from_github_no_auth.py
• get_from_github_with_auth.py
• get_from_gitlab_no_auth.py

Each uses the same pattern:

from backoff import expo
from backoff import on_exception

@on_exception(expo, RateLimitException, max_tries=8)
def get_from_github_no_auth(url, url_type):
    ...

Describe the solution you would like

Migrate to backon — a modern, actively maintained evolution of backoff. It is a drop-in replacement: change only the import statement in all 3 files.

-from backoff import expo, on_exception
+from backon import expo, on_exception

The dependency change in setup.py:

-"backoff==2.2.*",
+"backon>=4.3.0",

Why backon?

• Zero dependencies (pure Python, stdlib only)
• Same public API as backoff — on_exception, on_predicate, expo, fibo, constant, runtime
• Full type hints
• Python 3.10+ compatible (including 3.14+)
• Additional features: circuit breaker, hedging, testing utilities, global toggle
• Migration is trivial — just the import change

Describe alternatives you have considered

• tenacity — different API, would require rewriting all decorators.
• python-backoff — community fork, same API but no new features and still relies on deprecated APIs.
• Staying on backoff — archived, will break on Python 3.14+.

Additional context

• backon PyPI: https://pypi.org/project/backon/
• backon GitHub: https://github.com/Llucs/backon
• I am the author of backon and happy to submit a PR if desired.