Fix: prevent_self_review breaks all environment creation via .asf.yaml

[andrewmusselman]

Gotten this email message on two separate repos when setting up Trusted Publishing for PyPi and merging a new version of .asf.yaml setting up an environment pypi, first on apache/tooling-asfswhid and just now on apache/mahout:

mahout.git: Error while running github feature from main:.asf.yaml
[Mahout/dev]
Apache Infrastructure
12:06 AM (26 minutes ago)
to jiekaichang, commits
An error occurred while processing the github feature in .asf.yaml:

Repository.create_environment() got an unexpected keyword argument 'prevent_self_review'

---
With regards, ASF Infra.
For further information, please see the .asf.yaml documentation at:
https://github.com/apache/infrastructure-asfyaml/blob/main/README.md

create_environment() always passes prevent_self_review=True (the default) to PyGithub's Repository.create_environment(), but the installed PyGithub version does not support that parameter, causing a TypeError that prevents any deployment environment from being created.

This patch:

• Defaults prevent_self_review to None instead of True (only pass when explicitly set in .asf.yaml)
• Falls back gracefully if PyGithub raises TypeError on the parameter, retrying without it

[andrewmusselman]

I realized I hadn't specified the symptom in the trusted publishing workflow, which is we tag a release in git and push to github, and after ci/cd, the artifacts get sent to pypi without a maintainer approval gate.