Gitea 28.0 drops 1.x versioning, adds audit logs and bot accounts

Gitea 28.0 is out: the project dropped the historical 1.x prefix (former 1.28 is now 28.0) and added built-in audit logging with filtering and JSONL export, dedicated bot accounts for automation, and admin user impersonation. It also brings repository-scoped HTTPS deploy tokens, CODEOWNERS approval for pull requests, and Gitea Actions improvements.

• Audit logging is off by default and retains events for 30 days
• Bot accounts authenticate via tokens only and get no notifications
• Git 2.25+ is required and self-registration is disabled by default
• Gitea Actions runs are removed after 400 days by default