ci: require an infra review for CI and release scripts again #15

Problem

sdk-go's CODEOWNERS requires an @ai-openshell/infra review for .github/ and for the scripts its workflows run with the bot token. sdk-python starts without that rule. While the move is in progress, most of the infra team is in a US time zone, and the PRs needed for 0.1.8 (#3, #12, #13, #14) are almost all CI. An infra-only review would leave them waiting on a few people. For now the SDK team and the OpenShell maintainers own everything here.

Proposal

Once 0.1.8 is out and the automation runs, add the infra rule back, matching sdk-go:

# CI and the scripts it runs with the bot token or PyPI access need an infra review.
/.github/ @ai-openshell/infra
/scripts/core-sync/ @ai-openshell/infra
/scripts/release/ @ai-openshell/infra

Done when

The main ruleset already requires code owner review, so the rule takes effect as soon as it's added.

• .github/CODEOWNERS has the rule above, and the comment that points to this issue is removed.